Consolidate dozeAmountTransition into transitionValue(AOD)

This change gets rid of dozeAmountTransition because the function is
essentially the same as transitionValue with the exception that whole
steps are emitted instead of just the value.

Test: None
Bug: b/330311871
Flag: com.android.systemui.scene_container
Change-Id: I9fda746f0d68caec306e92a507c7fef6362d7670