Merge "Add support to persist app background restriction settings." into tm-dev am: 4935cbc6

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/17354264



Change-Id: I719aa564010544b264d3757c1719c4e320557166
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>