Merge "Prevent non-admin users from deleting system apps." into rvc-dev am: 71fad59e5e

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/19570390

Change-Id: I2bbb9bdd9f662be36a205565450282429fb58c82
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>