Stop removing all APP_STANDBY_BUCKET_CHANGED messages.

APP_STANDBY_BUCKET_CHANGED messages are for single apps, so it doesn't
make sense to remove all messages whenever any app's standby bucket
changes.

Bug: 193918191
Test: N/A
Change-Id: I981cd3be3cd381c6d00f06e3da9f8e67f157a26b
Merged-In: I981cd3be3cd381c6d00f06e3da9f8e67f157a26b

apex/jobscheduler/service/java/com/android/server/alarm/AlarmManagerService.java

@@ -4635,7 +4635,6 @@ public class AlarmManagerService extends SystemService {
                 Slog.d(TAG, "Package " + packageName + " for user " + userId + " now in bucket " +
                         bucket);
             }
-            mHandler.removeMessages(AlarmHandler.APP_STANDBY_BUCKET_CHANGED);
             mHandler.obtainMessage(AlarmHandler.APP_STANDBY_BUCKET_CHANGED, userId, -1, packageName)
                     .sendToTarget();
         }