Merge "Make getAliveUsers() and getUsers() as @TestApi." into udc-dev am: 7c8d60cd66 am: c279f8c5ef

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/22995969

Change-Id: I7c6172b26b11062b9451e09a272c4c8923cc49fc
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>