[automerger skipped] DO NOT MERGE Disallow Wallpaper service to launch activity from background. am: b7b2856de6 -s ours

am skip reason: subject contains skip directive

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/25329531

Change-Id: Id47747413ab347757cb1a9cd7fc528edfa0fae3c
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>