StreamingService: Wind down resources immediately after streaming.

Wind down resources immediately after streaming. A handler was set up initially
to allow the stream to come back up after a short period and to keep the
notification up for that short period but with the newer code that's
unnecessary.
NotificationService: onTrackChange() is never called with a blank playlist.
NotificationService: onStatusChange(), if blank playlist stop the notification.

It makes sense to stop or hide the notification if there is nothing in the
playlist as this will require manual user interaction.
StreamingService: At playlist completion, let onCompletion() handle stream end.

If the last song ends and the playlist is going to have a length of 0,
using onStateChange() will cut the final song off early due to buffering.
Instead, now check to see if the playlist is blank on stop and if so ignore
it and it will be handled in onComletion().
StreamingService: We're not an instance of Activity, skip to addConnectionLock.
StreamingService: Replace stopStreaming() with windDownResources().

stopStreaming got to a place where it was basically a call to
windDownResources()  with a intent call, and it makes sense for that intent
call to happen as an argument of windDownResources.