Add a layout that promotes the last chosen activity to the top for
ResolverActivity. Alter ResolverActivity behavior as appropriate: Only
the last selected activity can be set as default. Different activity
selections take effect immediately. You can only set a default if it
was the last-used target of the intent.
Also add some default strings for invoking common intents to make the
no-title invocations a bit more user-friendly than just, "complete
action using."
Bug 15694906
Change-Id: I8c75d2f812926805c949cc76bab48aa4094e002f