Make getPersonalAppsSuspensionReasons more robust.

* Make sure that if the time is rolled back after the deadline
  has been reached, it is not undone. When the deadline is
  reached it is set to -1 which is far in the past, so timezone
  change won't affect it.
* Return sensible value in case when the deadline has just
  expired and the suspension itself hasn't been enacted.
  Previously the deadline expiration wouldn't be reflected until
  mAppsSuspended gets updated after all apps are suspended.
* Update deadline on time changes. This makes it react to time
  changes via adb.
* Additional debug logging to investigate further if the issue
  persists.

Bug: 155878352
Test: atest com.android.server.devicepolicy.DevicePolicyManagerTest
Change-Id: I6549f76584121df200ace811285e7a358f262869