UserManager: Add new @SystemApis

There are already public versions of these APIs which allow
these queries for the calling app's user. Need to expose a version that
allows single instance apps, i.e user 0 (like wifi) to query info for
different users. The exposed APIs are:
a) isUserUnlockingOrUnlocked
b) isSameProfileGroup

Bug: 142024973
Test: Device boots up & connects to wifi networks
Change-Id: I77cd31a2344a6cbb272196523c10ad259aea74ce