fix: webview.postMessage throws not a constructor in WebView in Andro…

…id 4.1 ~ 4.3

Summary:
`new MessageEvent` not support for Android 4.1 ~ 4.3 WebView.

change

``` javascript
document.dispatchEvent(new MessageEvent('message', data)))
```

to

``` javascript
(function () {
  var event;
  var data = {};
  try {
    event = new MessageEvent('message', data);
  } catch (e) {
    event = document.createEvent('MessageEvent');
    event.initMessageEvent('message', true, true, data.data, data.origin, data.lastEventId, data.source);
  }
  document.dispatchEvent(event);
})()
```
Closes #11560

Differential Revision: D4461360

fbshipit-source-id: 110220817d9570e86b31dcf8fe85f6616d54d36e

ReactAndroid/src/main/java/com/facebook/react/views/webview/ReactWebViewManager.java

@@ -503,7 +503,17 @@ public void receiveCommand(WebView root, int commandId, @Nullable ReadableArray
         try {
           JSONObject eventInitDict = new JSONObject();
           eventInitDict.put("data", args.getString(0));
-          root.loadUrl("javascript:(document.dispatchEvent(new MessageEvent('message', " + eventInitDict.toString() + ")))");
+          root.loadUrl("javascript:(function () {" +
+            "var event;" +
+            "var data = " + eventInitDict.toString() + ";" +
+            "try {" +
+              "event = new MessageEvent('message', data);" +
+            "} catch (e) {" +
+              "event = document.createEvent('MessageEvent');" +
+              "event.initMessageEvent('message', true, true, data.data, data.origin, data.lastEventId, data.source);" +
+            "}" +
+            "document.dispatchEvent(event);" +
+          "})();");
         } catch (JSONException e) {
           throw new RuntimeException(e);
         }