Only call requestUnbind if we are connected.

Somethimes onSettingChanged can come after the connected has disconnected because
of posting message on the different thread.

Bug: 110929527
Change-Id: I09f503c2f2f437c8656d491a7fdec3ce4e82257b

src/com/android/launcher3/notification/NotificationListener.java

@@ -197,7 +197,7 @@ public class NotificationListener extends NotificationListenerService {
         mNotificationBadgingObserver = new SettingsObserver.Secure(getContentResolver()) {
             @Override
             public void onSettingChanged(boolean isNotificationBadgingEnabled) {
-                if (!isNotificationBadgingEnabled) {
+                if (!isNotificationBadgingEnabled && sIsConnected) {
                     requestUnbind();
                 }
             }