Shortcuts alpha should only react to shadeExpansion when on Lockscreen

Shade expansion was sending a 0f while going from GONE -> AOD

Then during AOD -> LOCKSCREEN, due to the shade expansion value, the
shortcuts were flickering one frame of 1f alpha.

The shortcuts should only be reacting to shade expansion on LOCKSCREEN

Fixes: 325329538
Test: KeyguardQuickAffordancesCombinedViewModelTest.kt
Flag: ACONFIG com.android.systemui.keyguard_bottom_area_refactor TEAMFOOD
Change-Id: I90c218346ff265352de02be955d62cf9a41404ed