[flexiglass] Add view+viewmodel layer support for 2-line bouncer messages

Summary of changes:
 - Remove the stored bouncer message state in BouncerRepository (and any code that resets that state)
 - Always show the default message on bouncer.
 - Add a new Text view to show the second line bouncer message
 - Listen for any device entry restriction and update the displayed bouncer message
 - Listen for any events from the bouncer (user input, incorrect auth, lockout started) and update the message
 - Listen for any events from the face/fingerprint auth (help messages, failure, lockout messages) and update the message
 - Listen for any events from the SIM bouncer and update the message shown.

Fixes: 299343534
Test: all unit tests pass, verified manually on the compose bouncer
Flag: ACONFIG com.android.systemui.compose_bouncer DEVELOPMENT
Change-Id: I064c31b86c663ab76228525565bad3df9881b6e8