[automerger skipped] Add Restricted Mode settings observer to NetworkPolicyManagerService am: 8b6082b585 am: f2832ba483 am: d5475db15a -s ours

am skip reason: Change-Id Ie9456f6a0b8d6d4e8e4bdfc3f6954e247fd9c5fb with SHA-1 e8abd9e6c3 is in history

Original change: https://android-review.googlesource.com/c/platform/frameworks/base/+/1545866

MUST ONLY BE SUBMITTED BY AUTOMERGER

Change-Id: I732df990a4c72ec47e7c7750c62e18b020f8acdb