Initial commit of rotation contextual button.

UI fixing todo: b/187754252

Bug: 180046394
Test: Works in basic cases with on home and
in app taskbar.

Change-Id: I69985b57e38a9fdb7935fcafb097b1e6da73a6b9
diff --git a/quickstep/res/layout/taskbar.xml b/quickstep/res/layout/taskbar.xml
index e680233..d32c115 100644
--- a/quickstep/res/layout/taskbar.xml
+++ b/quickstep/res/layout/taskbar.xml
@@ -29,7 +29,7 @@
         android:layout_gravity="bottom" >
 
         <LinearLayout
-            android:id="@+id/system_button_layout"
+            android:id="@+id/nav_button_layout"
             android:layout_width="wrap_content"
             android:layout_height="wrap_content"
             android:paddingLeft="@dimen/taskbar_nav_buttons_spacing"
@@ -44,6 +44,15 @@
             android:forceHasOverlappingRendering="false"
             android:gravity="center" />
 
+        <LinearLayout
+            android:id="@+id/contextual_button_layout"
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:paddingLeft="@dimen/taskbar_nav_buttons_spacing"
+            android:paddingRight="@dimen/taskbar_nav_buttons_spacing"
+            android:forceHasOverlappingRendering="false"
+            android:gravity="center" />
+
     </com.android.launcher3.taskbar.TaskbarView>
 
     <com.android.launcher3.taskbar.ImeBarView