Add location notification and target sdk checks

Check target SDKs to disallow using setSecureSetting with LOCATION_MODE
and point clients to setLocationEnabled() instead. Show notifications to
users when location settings are changed by the admin.

Bug: 136219903
Test: manual - triggered setLocationEnabled and observed notification
Change-Id: I07c150e62230b06f76ec7bd5197a23e703ffb918