Fix tab elevation for action bar placeholder.

Bug: 19644830
Change-Id: Ib6949e6dcfad006256b18465db450b2edc2385e6
diff --git a/res/layout/lists_fragment.xml b/res/layout/lists_fragment.xml
index bcf414b..1942a96 100644
--- a/res/layout/lists_fragment.xml
+++ b/res/layout/lists_fragment.xml
@@ -32,7 +32,8 @@
         <FrameLayout
             android:layout_width="match_parent"
             android:layout_height="@dimen/action_bar_height_large"
-            android:background="@color/actionbar_background_color" />
+            android:background="@color/actionbar_background_color"
+            android:elevation="@dimen/tab_elevation" />
 
         <com.android.contacts.common.list.ViewPagerTabs
             android:id="@+id/lists_pager_header"