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: I8f57f2990d6c1e2b0f52331bf6f7d1663cf66ad1
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>