Fade as shade expands

This was most notable in splitshade, as the clock
could appear above QS.

Fixes: 325438424
Test: atest KeyguardRootViewModelTest
Flag: ACONFIG com.android.systemui.migrate_clocks_to_blueprint
DEVELOPMENT

Change-Id: I788a940f1b36465757f343c4f7677a96749a76df
3 files changed