fix error in ReactViewGroup (#113)

Author: SzymczakJ

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/views/view/ReactViewGroup.java

@@ -649,6 +649,8 @@ public void onViewAdded(View child) {
 
   @Override
   public void onViewRemoved(View child) {
+    Object nativeId = child.getTag(R.id.view_tag_native_id);
+
     try {
       Object childNativeId = child.getTag(R.id.view_tag_native_id);
       if (nativeId instanceof String) {
@@ -657,11 +659,11 @@ public void onViewRemoved(View child) {
                 .anyMatch(nativeID::equals);
         if (matches) {
           String stackTrace = android.util.Log.getStackTraceString(new Throwable());
-          FLog.e(ReactConstants.TAG, "onViewRemoved of one of the tracked children: " + nativeID + " with stack trace: " + "\n" + stackTrace);
+          FLog.e(TAG, "onViewRemoved of one of the tracked children: " + nativeID + " with stack trace: " + "\n" + stackTrace);
         }
       }
     } catch (Exception e) {
-      FLog.e(ReactConstants.TAG, "Exception in getting onViewRemoved info: " + e.getMessage());
+      FLog.e(TAG, "Exception in getting onViewRemoved info: " + e.getMessage());
     }
 
     UiThreadUtil.assertOnUiThread();