Add trace points for measuring performance

Test: systrace
Bug: 139363827
Bug: 139360025
Change-Id: I979c5fbecbaa9896a39abeb7b5639a95a5166688

packages/SystemUI/src/com/android/systemui/statusbar/policy/KeyguardStateControllerImpl.java

@@ -154,13 +154,17 @@ public class KeyguardStateControllerImpl extends KeyguardUpdateMonitorCallback
     }
 
     private void notifyKeyguardChanged() {
+        Trace.beginSection("KeyguardStateController#notifyKeyguardChanged");
         // Copy the list to allow removal during callback.
         new ArrayList<>(mCallbacks).forEach(Callback::onKeyguardShowingChanged);
+        Trace.endSection();
     }
 
     private void notifyUnlockedChanged() {
+        Trace.beginSection("KeyguardStateController#notifyUnlockedChanged");
         // Copy the list to allow removal during callback.
         new ArrayList<>(mCallbacks).forEach(Callback::onUnlockedChanged);
+        Trace.endSection();
     }
 
     @Override