Fix overdraw in Dialer

* Set window background to null per framework advice to reduce
overdraw
* Remove unnecessary background layers
* Fix the slightly deeper gray background above the searchbox
Bug: 10446771

Change-Id: Ie11db155593c7ea2118141aec876da37be35a7d5
diff --git a/res/layout/phone_favorites_fragment.xml b/res/layout/phone_favorites_fragment.xml
index d1ff3d7..4992486 100644
--- a/res/layout/phone_favorites_fragment.xml
+++ b/res/layout/phone_favorites_fragment.xml
@@ -21,8 +21,7 @@
     android:layout_height="match_parent"
     android:divider="?android:attr/dividerHorizontal"
     android:showDividers="end"
-    android:clipChildren="false"
-    android:background="@color/background_dialer_list_items">
+    android:clipChildren="false">
 
     <FrameLayout
         android:id="@+id/contact_tile_frame"