[automerger skipped] DO NOT MERGE: Fix ActivityManager#killBackgroundProcesses permissions am: 140fce8619 am: 18b4a887a2 -s ours

am skip reason: subject contains skip directive

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/25119905

Change-Id: I6c2e187d1c0da9ea8761fe6c214fef9adba3fc0f
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>