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

Merge "Conform the logic to decide wallpaper darkness" into udc-dev am: 223a0a22 am: 175850f9 am: 749dc458 am: 7140a725

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/23617998



Change-Id: I4d75176bdc7460e6297ffe76b05d2d5cbc4452b0
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>