MAP: Fix ANR due wait on shutdown complete.

Remove wait for shutdown to complete on main
thread. Perform cleanup for handler and quit
looper from closeService running on worker
thread on first SHUTDOWN message.

Check and allow posting of SHUTDOWN message
only if later doesnt not already exists in
mSessionStatusHandler message queue.

CRs-Fixed: 975531

Change-Id: I67d90a8d97aebd055286029c0ccf39126a62e8ba