[flexiglass] Hookup new source of truth for bouncer states in KeyguardUpdateMonitor

In legacy code, keyguardUpdateMonitor relies on bouncer states to be
passed to it via StatusBarKeyguardViewManager. Rather than relying
on SBKVM, rely on the SceneInteractor for primary bouncer states
and rely on the AlternateBouncerInteractor for the alternate
bouncer visibility state.

Test: atest KeyguardUpdateMonitorTest StatusBarKeyguardViewManagerTest
Bug: 353955910
Bug: 357649556
Flag: com.android.systemui.scene_container
Change-Id: I83a492a16ff5661110ba1af16ce9dcd2bd2ea082