Add UI asserts and logs to a few more places

Summary:
Add UI asserts to ensure thread safety of some operations.

Changelog: [Internal]

Reviewed By: mdvacca

Differential Revision: D18339981

fbshipit-source-id: 9162b6351f40bdd543d3e255691e9f54d1934589

ReactAndroid/src/main/java/com/facebook/react/uimanager/NativeViewHierarchyManager.java

@@ -484,6 +484,10 @@ public class NativeViewHierarchyManager {
               new LayoutAnimationListener() {
                 @Override
                 public void onAnimationEnd() {
+                  // This should be called only on the UI thread, because
+                  // onAnimationEnd is called (indirectly) by Android View Animation.
+                  UiThreadUtil.assertOnUiThread();
+
                   viewManager.removeView(viewToManage, viewToDestroy);
                   dropView(viewToDestroy);