Add new APIs setAutoTimeZone and getAutoTimeZone

* Added new API methods setAutoTimeZone and getAutoTimeZone.
* DPCs are recommended to combine these new APIs together with the DISALLOW_CONFIG_DATE_TIME
  restriction to prevent the user from changing auto time zone settings.
* The new methods can also be called by the WP PO (COPE mode).

Bug: 138709470
Test: Manual testing with testdpc and the set auto time zone toggle
      atest com.android.server.devicepolicy.DevicePolicyManagerTest
      atest com.android.cts.devicepolicy.MixedProfileOwnerTest#testSetAutoTimeZone
      atest com.android.cts.devicepolicy.ManagedProfileTest#testParentProfileApiDisabled

Change-Id: I841d31f76a848e9679d2d9087426e1d5bb7efd1d