Fix WakeLock issue for driver stop

Due to message removal, wakelock could be held forever.

Do a timer only based wakelock release until we do this
more cleanly in ConnectivityService for later release.

Also, add an optimization to prevent use of wakelocks when driver is
already stopped.

Bug: 2529883
Change-Id: Ia1c2ddd44213ef3aa609855613bf155945bef8e4