Listen for policy change that affect time/tz

Listen for policy change that could affect time/tz rights for the
current user.

The current policy restrictions for a user can change. This adds
listener registration that ensures that the cached configuration for the
current user is updated when this happens without the device also being
rebooted.

Bug: 333737037
Test: Manual, see b/333737037
Test: Treehugger
Change-Id: I3383707d2243b9bc20b9e0bdf41064d19c03065f