Merge \"Use colorAccent for fullscreen tutorial.\" into nyc-mr1-dev

am: 5494983425

Change-Id: Ife4d06ed28801ce0028c0fa7c77a791c0f5aec4d

core/res/res/layout/immersive_mode_cling.xml

@@ -16,7 +16,7 @@
 <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
         android:layout_width="match_parent"
         android:layout_height="wrap_content"
-        android:background="#ff009688"
+        android:background="?android:attr/colorAccent"
         android:gravity="center_vertical"
         android:paddingBottom="24dp">
 
@@ -47,7 +47,7 @@
                 android:paddingTop="8dp"
                 android:scaleType="center"
                 android:src="@drawable/ic_expand_more_48dp"
-                android:tint="#ff009688"/>
+                android:tint="?android:attr/colorAccent"/>
     </FrameLayout>
 
     <TextView