Add shell command to query Restricted Mode state am: ce9f94d956 am: 791ea8a405 am: 429f94a923

Original change: https://android-review.googlesource.com/c/platform/frameworks/base/+/1545867

MUST ONLY BE SUBMITTED BY AUTOMERGER

Change-Id: I96e6a1ce24de28f4a5635f095ce9387f73b407db