Implement listener to notify clients of updates to secure lock device status

Implement listener registration for updates to secure lock device
status. This includes whether secure lock device is enabled or disabled,
and whether secure lock device is available

Flag: android.security.secure_lock_device
Fixes: 406265894
Bug: 401645997
Test: atest SecureLockDeviceServiceTest
Test: atest CtsSecurityTestCases:android.security.cts.authenticationpolicy.AuthenticationPolicyManagerTest
Change-Id: I4b72927a98939d7f40ca290ea4db99dbaa5060a8