Change id "root" to "movie_view_root" to avoid confusion.

There is also one id "root" in Camera.

Change-Id: Id6ebc5362f5ddceabe6dab6218de9b091454bde7
diff --git a/src/com/android/gallery3d/app/MovieActivity.java b/src/com/android/gallery3d/app/MovieActivity.java
index 9ad63db..4df84f4 100644
--- a/src/com/android/gallery3d/app/MovieActivity.java
+++ b/src/com/android/gallery3d/app/MovieActivity.java
@@ -57,7 +57,7 @@
         requestWindowFeature(Window.FEATURE_ACTION_BAR_OVERLAY);
 
         setContentView(R.layout.movie_view);
-        View rootView = findViewById(R.id.root);
+        View rootView = findViewById(R.id.movie_view_root);
         Intent intent = getIntent();
         initializeActionBar(intent);
         mFinishOnCompletion = intent.getBooleanExtra(