Merge "Conform the logic to decide wallpaper darkness" into udc-dev am: 223a0a22

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



Change-Id: I700442ccc6330e1c932d58ddfa61c680912e1724
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>