Fix 6507787: fix MMI PUK unlock procedure

This fixes a bug where the user uses the MMI sequence (**05*PUK*PIN1*PIN1#)
from the EmergencyDialer to unlock their phone instead of the provided interface.

The code now recognizes when UnlockMode becomes invalid because it was previously
locked because of SIM state. It then dismisses the PUK unlock screen and advances
to the home screen.

Change-Id: I8902350e6f640cd2fa0af3460c3ea1a39d926c8a