Stop persisting SMS into OUTBOX before sending

Persisting SMS into OUTBOX before sending proved to cause
problems with Messaging app (and potentially other apps) that could try
sending messages in OUTBOX without being asked as manifested in bug
b/18155366. This CL only presists SMS after it is being sent.

b/18202414

Change-Id: Ie0d0e088549bf0853b364e4d33eed2a5d79a7758