Merge "Conform the logic to decide wallpaper darkness" into udc-dev am: 4f7f216c1f

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/apps/ThemePicker/+/23618530

Change-Id: I92989b35d8acec818152b26b458e38e553d59d84
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>