Corrected a non fatal exception if contentView has a parent already

Auditors: @bbondy

Author: SergeyZhukovsky

Application/LinkBubble/src/main/java/com/linkbubble/ui/CanvasView.java

@@ -462,7 +462,9 @@ public void onBeginExpandTransition(MainController.BeginExpandTransitionEvent e)
         fadeIn();
 
         if (mContentView != null) {
-            addView(mContentView);
+            if (null == mContentView.getParent()) {
+                addView(mContentView);
+            }
             mContentView.onAnimateOnScreen();
             showContentView();
         }