Add PlaybackOverlayFragment

Change-Id: If4c5b2f747885948e0bae422d9d30eec11c027b9

samples/SupportLeanbackDemos/res/layout/playback_controls.xml

@@ -0,0 +1,23 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+     Copyright (C) 2014 The Android Open Source Project
+
+     Licensed under the Apache License, Version 2.0 (the "License");
+     you may not use this file except in compliance with the License.
+     You may obtain a copy of the License at
+
+          http://www.apache.org/licenses/LICENSE-2.0
+
+     Unless required by applicable law or agreed to in writing, software
+     distributed under the License is distributed on an "AS IS" BASIS,
+     WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+     See the License for the specific language governing permissions and
+     limitations under the License.
+-->
+
+<fragment xmlns:android="http://schemas.android.com/apk/res/android"
+    android:name="com.example.android.leanback.PlaybackOverlayFragment"
+    android:id="@+id/playback_controls_fragment"
+    android:layout_width="match_parent"
+    android:layout_height="match_parent"
+/>