Revert "Add UID permission check to update_engine" am: eceec328e2 am: 4c2cb8a5da am: 31fed1366b am: 7446fc3f10

Original change: https://android-review.googlesource.com/c/platform/system/update_engine/+/2776588

Change-Id: I1c5f1e978b21a9d9be94656ec09393b68136f5f2
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>