KeyguardUpdateMonitor's Handler runs on the main looper by design, we need to ensure that whenever we're processing messages, that they will also be received on the main looper. Also unregistered a broadcast listener to avoid a possible race condition Test: atest packages/SystemUI/tests/src/com/android/keyguard/KeyguardUpdateMonitorTest.java Bug: 79550837 Change-Id: I14a319da5c6bc46fd32675ae205e14a6228efaa4