fix. android native secret key nil

android/build.gradle

 apply plugin: 'com.android.library'
 
+allprojects {
+    gradle.projectsEvaluated {
+        tasks.withType(JavaCompile) {
+            options.encoding = 'utf-8'
+            options.compilerArgs << "-Xlint:deprecation"
+        }
+    }
+}
+
 buildscript {
     repositories {
         google()
     mavenCentral()
     mavenLocal()
     maven {
-        url "file:///Users/ly/GithubPremium/react-native-agora/node_modules/react-native"
+        url "$rootDir/../node_modules/react-native/android"
     }
     jcenter()
     google()

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

         //create rtcEngine instance and setup rtcEngine eventHandler
         try {
             mRtcEngine = RtcEngine.create(context, options.getString("appid"), mRtcEventHandler);
-            if (null != options.getString("secret")) {
+            if (options.hasKey("secret") && null != options.getString("secret")) {
                 mRtcEngine.setEncryptionSecret(options.getString("secret"));
-                if (null != options.getString("secretMode")) {
+                if (options.hasKey("secretMode") && null != options.getString("secretMode")) {
                     mRtcEngine.setEncryptionMode(options.getString("secretMode"));
                 }
             }