-Added basic UI for local playlists.

-Added UI for watch history and most played fragments.
-Added stream state table for storing playback timestamp and future usage.
-Enabled playlist deletion.

app/src/main/res/layout/fragment_subscription.xml

@@ -27,7 +27,7 @@
 
     <include
         android:id="@+id/empty_state_view"
-        layout="@layout/subscription_feed_empty_view"
+        layout="@layout/list_empty_view"
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:layout_centerInParent="true"