Allow granular ambient suppression.

This changelist introduces a flag based approach for specifying how
the ambient display should be suppressed. This replaces the existing
binary signal and allows for dreams, aod, or the entire display to
be suppressed.

Test: atest PowerManagerServiceTest
Bug: 408229468
Flag: android.os.low_light_dream_behavior

Change-Id: I1f285f2b499e5bd6773a600e2470114678dbefd8