Fix race condition with notif alpha

Sometimes when unlocking via bouncer and not expanding
the shade, the alpha is left at 0f which will prevent
HUN from being visible.

Fixes: 353717873
Test: atest PrimaryBouncerToGoneTransitionViewModelTest
Flag: com.android.systemui.migrate_clocks_to_blueprint
Change-Id: I3dc9a8ce33514be168300298307ddfc24bb22188