chore. update changelog

CHANGELOG

 ## THE CHANGELOG
 
+#### 2.4.1-alpha
+- support 2.4.1-alpha.1 agora video sdk android-2.4.1 / iOS-2.4.1
+  1. Deprecate iOS
+  2. Add methods getAudioMixingPlayoutVolume, getAudioMixingPublishVolume for audio mixing troubleshooting.
+  3. Add `txPacketLossRate`, `rxPacketLossRate` on `rtcStats` interface. usage: `RtcEngine.on('rtcStats', (data) => console.log(data))`.
+  4. Rename `receivedFrameRate` to `rendererOutputFrameRate` this property related on `localVideoStats` and `remoteVideoStats`.
+  5. Add event 'localVideoChanged' and Deprecate events `cameraReady` and `videoStopped`. You can listen `localVideoChanged` event instead  `cameraReady` & `videoStopped`.
+  6. Add event `rtmpStreamingStateChanged` for rtmp streaming troubleshooting
+  7. Add event `audioCodecProfile` on `liveTranscoding` interface.
+  8. Add event `networkTypeChanged` for network troubleshooting.
+  9. Add method `registerMediaMetadataObserver` method, this method enables you to add synchronized metadata in the video stream for more diversified live broadcast interactions, such as sending shopping links, digital coupons, and online quizzes. note: Call this method before the joinChannel method. and applies to `channelProfile` with 1. 
+  10. Add method `sendMediaData`, this method enables you send media data under the live broadcast mode (`channelProfile` = 1) note: call this method after the `registerMediaMetadataObserver` method.
+  11. Add event `audioMixingStateChanged` and Deprecate event 'localAudioMixingFinish`.
+  11. Add `firstRemoteAudioDecoded` event you can get more detail [here](https://docs.agora.io/en/Interactive%20Broadcast/release_android_video?platform=Android#v241)
 
 #### 2.4.0-alpha
 - support 2.4.0-alpha.1 agora video sdk android-2.4.0 / iOS-2.4.0.1 and add sendMessage support in the same channel. Deprecate: startEchoTest and setVideoQualityParameters

android/src/main/java/com/syan/agora/AgoraModule.java

     private final static String AGNetworkTypeChanged = "networkTypeChanged";
     private final static String AGFirstRemoteAudioDecoded = "firstRemoteAudioDecoded";
     private final static String AGMediaMetaDataReceived = "mediaMetaDataReceived";
+    private final static String AGLocalVideoChanged = "localVideoChanged";
     private final static String AGRemoteVideoStateChanged = "remoteVideoStateChanged";
     private final static String AGLocalPublishFallbackToAudioOnly = "localPublishFallbackToAudioOnly";
     private final static String AGRemoteSubscribeFallbackToAudioOnly = "remoteSubscribeFallbackToAudioOnly";
     private final static String AGAudioTransportStatsOfUid = "audioTransportStatsOfUid";
     private final static String AGVideoTransportStatsOfUid = "videoTransportStatsOfUid";
 
-    private final static String AGLocalAudioMixingFinish = "localAudioMixingFinish";
     private final static String AGRemoteAudioMixingStart = "remoteAudioMixingStart";
     private final static String AGRemoteAudioMixingFinish = "remoteAudioMixingFinish";
     private final static String AGAudioEffectFinish = "audioEffectFinish";
+    private final static String AGAudioMixingStateChanged = "audioMixingStateChanged";
 
     private final static String AGStreamPublished = "streamPublished";
     private final static String AGStreamUnpublish = "streamUnpublish";
             });
         }
 
-//        @Override
-//        public void onVideoStopped() {
-//            runOnUiThread(new Runnable() {
-//                @Override
-//                public void run() {
-//                    WritableMap map = Arguments.createMap();
-//                    map.putString("message", "VideoStopped");
-//                    sendEvent(getReactApplicationContext(), AGVideoStopped, map);
-//                }
-//            });
-//        }
-
         @Override
         public void onFirstLocalVideoFrame(final int width, final int height, final int elapsed) {
             runOnUiThread(new Runnable() {
             });
         }
 
-        @Override
-        public void onCameraReady() {
-            runOnUiThread(new Runnable() {
-                @Override
-                public void run() {
-                    WritableMap map = Arguments.createMap();
-                    map.putString("message", "CameraDidReady");
-                    sendEvent(getReactApplicationContext(), AGCameraReady, map);
-                }
-            });
-        }
-
         @Override
         public void onCameraFocusAreaChanged(final Rect rect) {
             runOnUiThread(new Runnable() {
                     statsMap.putInt("userCount", stats.users);
                     statsMap.putDouble("cpuAppUsage", stats.cpuAppUsage);
                     statsMap.putDouble("cpuTotalUsage", stats.cpuTotalUsage);
+                    statsMap.putInt("txPacketLossRate", stats.txPacketLossRate);
+                    statsMap.putInt("rxPacketLossRate", stats.rxPacketLossRate);
 
                     WritableMap map = Arguments.createMap();
                     map.putMap("stats", statsMap);
         }
 
         @Override
-        public void onAudioMixingFinished() {
+        public void onAudioMixingStateChanged(final int state, final int errorCode) {
             runOnUiThread(new Runnable() {
                 @Override
                 public void run() {
                     WritableMap map = Arguments.createMap();
-                    map.putString("message", "LocalAudioMixingSucceedFinish");
-                    sendEvent(getReactApplicationContext(), AGLocalAudioMixingFinish, map);
+                    map.putInt("state", state);
+                    map.putInt("errorCode", errorCode);
+                    sendEvent(getReactApplicationContext(), AGAudioMixingStateChanged, map);
                 }
             });
         }
                 }
             });
         }
+
+        @Override
+        public void onLocalVideoStateChanged(final int localVideoState, final int error) {
+            super.onLocalVideoStateChanged(localVideoState, error);
+            runOnUiThread(new Runnable() {
+                @Override
+                public void run() {
+                    WritableMap map = Arguments.createMap();
+                    map.putString("message", "LocalVideoChanged");
+                    map.putInt("state", localVideoState);
+                    sendEvent(getReactApplicationContext(), AGLocalVideoChanged, map);
+                }
+            });
+        }
     };
 
     @ReactMethod
             int res = AgoraManager.getInstance().mRtcEngine.getAudioMixingPlayoutVolume();
             if (res < 0) throw new ReactNativeAgoraException("getAudioMixingPlayoutVolume Failed", res);
             WritableMap map = Arguments.createMap();
-            map.putString("volume", Integer.toString(res));
+            map.putBoolean("success", true);
+            map.putInt("value", res);
             promise.resolve(map);
         } catch (Exception e) {
             promise.reject("-1", e);

ios/RCTAgora/AgoraConst.h

 static NSString *AGAudioTransportStatsOfUid = @"audioTransportStatsOfUid";
 static NSString *AGVideoTransportStatsOfUid = @"videoTransportStatsOfUid";
 
-static NSString *AGLocalAudioMixingFinish = @"localAudioMixingFinish";
 static NSString *AGRemoteAudioMixingStart = @"remoteAudioMixingStart";
 static NSString *AGRemoteAudioMixingFinish = @"remoteAudioMixingFinish";
 static NSString *AGAudioEffectFinish = @"audioEffectFinish";

ios/RCTAgora/RCTAgora.m

 RCT_EXPORT_METHOD(registerMediaMetadataObserver
                   :(RCTPromiseResolveBlock)resolve
                   reject:(RCTPromiseRejectBlock)reject) {
-  BOOL res = [_rtcEngine setMediaMetadataDataSource:self withType:AgoraMetadataTypeVideo];
-  if (res == YES) {
+  if (YES == [_rtcEngine setMediaMetadataDataSource:self withType:AgoraMetadataTypeVideo] &&
+    YES == [_rtcEngine setMediaMetadataDelegate:self withType:AgoraMetadataTypeVideo]
+    ) {
     resolve(@{
               @"success": @(YES)
               });
                                                                              @"code": @(-1),
                                                                              @"message":@{
                                                                                  @"success": @(NO),
-                                                                                 @"value":[NSNumber numberWithInteger:res]
+                                                                                 @"value":@(0)
                                                                                  }
                                                                              }]);
   }
            AGAudioTransportStatsOfUid,
            AGVideoTransportStatsOfUid,
            
-           AGLocalAudioMixingFinish,
+           AGAudioMixingStateChanged,
            AGRemoteAudioMixingStart,
            AGRemoteAudioMixingFinish,
            AGAudioEffectFinish,
            AGMediaEngineLoaded,
            AGMediaEngineStartCall,
            AGIntervalTest,
-           AGAudioMixingStateChanged,
            AGLastmileProbeTestResult,
            AGRtmpStreamingStateChanged,
            AGLocalVideoChanged,
                                                     }];
 }
 
-- (void)rtcEngineLocalAudioMixingDidFinish:(AgoraRtcEngineKit *_Nonnull)engine {
-  [self sendEvent:AGLocalAudioMixingFinish params:@{
-                                                     @"message": @"LocalAudioMixingSucceedFinish"
-                                                     }];
-}
-
 - (void)rtcEngineRemoteAudioMixingDidStart:(AgoraRtcEngineKit *_Nonnull)engine {
   [self sendEvent:AGRemoteAudioMixingStart params:@{
                                                      @"message": @"RemoteAudioMixingStarted"