Customizable lock screen affordance entry-point. am: abda67b66e

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/apps/ThemePicker/+/20601630

Change-Id: I6078aef1e634239fe6f61ad68468a397f2f45c7e
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>