Merge "Removing non SYSTEM user before running systemUserOnlyTest" into udc-dev-plus-aosp am: aeadff89d1

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/25176948

Change-Id: I3aae52efe951c551c4dceb3a24ac079a5d4b1de1
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>