Transitions - Add GONE state

When keyguard is dismissed, transition to a new GONE state. This helps
address an issue with the ClockEventController, where the clock was
not properly animating back to its AOD state.

Adding audit capability via KeyguardTransitionAuditLogger

Migrated to MutableSharedFlow. MutableStateFlow was conflating too
many events, some of them fairly important.

Test: atest ClockEventControllerTest KeyguardRepositoryImplTest
KeyguardTransitionRepositoryTest KeyguardTransitionInteractorTest
Bug: 195430376

Change-Id: Ic4bd48cea6e783cfdc116fa2776639da0641c100