[1/N] Make alternateBouncer its own view

With this flag enabled...
- AlternateBouncer shows over the lockscreen and notification
  shade (which is why it lives in super_notification_shade
  instead of the KeyguardRootView)
- AlternateBouncer has its own clickhandler so touches no longer
  need to be intercepted by the NotificationWindowView. Updated
  StatusBarTouchableRegionManager to include allowing touches
  when the AlternateBouncer is showing.
- AlternateBouncer "scrim" isn't relying on ScrimController and
  instead uses its own ScrimView.

This doesn't support the alternateBouncer message area nor swiping
on the alternate bouncer view => primary bouncer interactions.

Test: atest CentralSurfacesImplTest
Test: atest StatusBarKeyguardViewManagerTest
Test: atest AlternateBouncerViewModelTest
Test: adb shell cmd statusbar flag alternate_bouncer_view true
Bug: 300440924
Bug: 287599719
Change-Id: Ib51e7c3468f2607efc2dc9df531d26582120a041