T9 Dialer : Update upon contact info changes

Refresh the local storage of contact info if contact info is updated
while dialer is still active.

Patchset 2 : cleanup
Patchset 3 : Move unregister to onResume (Can't rely on activty being present)

Change-Id: I6ab4fe199ebc67c318217ab20aa1718a02fcbcaa