hal: Expand the list of Barge-in usecases

This change adds new usecases to the list that will raise a
usecase event to sthal. USECASE_AUDIO_PLAYBACK_LOW_LATENCY and
USECASE_AUDIO_PLAYBACK_ULL are added with system property checks.
USECASE_AUDIO_PLAYBACK_MMAP is also added without a system
property. Additionally, screen state events can now be sent to
sthal.

Change-Id: I936b2390d886b67695daf184a2ca1b018ed17567