Fix AOD icon flicker during GONE->AOD

Visibility was being changed during GONE-AOD transition. Disallow this
and make sure the alpha/visibility states are consistent

Fixes: 322157767
Test: atest KeyguardRootViewModelTest
Test: use GONE->AOD and observe notif icons state changes
Flag: ACONFIG com.android.systemui.keyguard_shade_migration_nssl
DEVELOPMENT

Change-Id: I321d80232799bc649840a35feba598c8281c454e