fix(android): onMessage on android to return baseEvent(#755)

android/src/main/java/com/reactnativecommunity/webview/RNCWebViewManager.java

     }
 
     public void onMessage(String message) {
-      dispatchEvent(this, new TopMessageEvent(this.getId(), message));
+      if (mRNCWebViewClient != null) {
+        WebView webView = this;
+        webView.post(new Runnable() {
+          @Override
+          public void run() {
+            WritableMap data = mRNCWebViewClient.createWebViewEvent(webView, webView.getUrl());
+            data.putString("data", message);
+            dispatchEvent(webView, new TopMessageEvent(webView.getId(), data));
+          }
+        });
+      } else {
+        WritableMap eventData = Arguments.createMap();
+        eventData.putString("data", message);
+        dispatchEvent(this, new TopMessageEvent(this.getId(), eventData));
+      }
     }
 
     protected void onScrollChanged(int x, int y, int oldX, int oldY) {

android/src/main/java/com/reactnativecommunity/webview/events/TopMessageEvent.kt

 package com.reactnativecommunity.webview.events
 
-import com.facebook.react.bridge.Arguments
+import com.facebook.react.bridge.WritableMap
 import com.facebook.react.uimanager.events.Event
 import com.facebook.react.uimanager.events.RCTEventEmitter
 
 /**
  * Event emitted when there is an error in loading.
  */
-class TopMessageEvent(viewId: Int, private val mData: String) : Event<TopMessageEvent>(viewId) {
+class TopMessageEvent(viewId: Int, private val mEventData: WritableMap) : Event<TopMessageEvent>(viewId) {
   companion object {
     const val EVENT_NAME = "topMessage"
   }
   override fun getCoalescingKey(): Short = 0
 
   override fun dispatch(rctEventEmitter: RCTEventEmitter) {
-    val data = Arguments.createMap()
-    data.putString("data", mData)
-    rctEventEmitter.receiveEvent(viewTag, EVENT_NAME, data)
+    rctEventEmitter.receiveEvent(viewTag, EVENT_NAME, mEventData)
   }
 }