Prevent non-admin users from deleting system apps. am: 6c870e15 am: 15ab50ec am: d719add2

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/17408864



Change-Id: Ibc618f6b6c33f0635acb6aae640e31a04044645b
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>