Merge "Merge "Add a callback to listen to uid foreground-ness change." into udc-dev am: b0302b10 am: 31fb0397" into udc-d1-dev-plus-aosp am: a974c029 am: 2d439dee

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/22499498



Change-Id: I118e25f8d8e6c89fed07c3ce0b2f03f9a3a922c0
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>