UI tweaks.

Hide disabled routes from the chooser.

Fix layout of chooser dialog when the settings button is visible and
the list is very long to prevent truncation of the settings button.

Fix an issue when we fake the route connecting status when a route
is selected.  The route changed notification needs to be propagated
to apps.  Fake it better.

Immediately disconnect from a route when the connection is lost or
a connection attempt fails.  Added a few new test displays for this
case.

Bug: 11257292
Change-Id: I360ab5dc937ad60d97592eab54b19f034519645e

core/res/res/layout/media_route_chooser_dialog.xml

@@ -23,7 +23,8 @@
     <!-- List of routes. -->
     <ListView android:id="@+id/media_route_list"
               android:layout_width="match_parent"
-              android:layout_height="wrap_content" />
+              android:layout_height="wrap_content"
+              android:layout_weight="1" />
 
     <!-- Content to show when list is empty. -->
     <LinearLayout android:id="@android:id/empty"