Safeguard from monkeys.

Bug: 6315950
Change-Id: I680b3f0a2cee565a39d58e95a8abe5f62cc7b466

src/com/android/settings/applications/RunningServiceDetails.java

@@ -554,6 +554,7 @@ public class RunningServiceDetails extends Fragment
 
     @Override
     public void onRefreshUi(int what) {
+        if (getActivity() == null) return;
         switch (what) {
             case REFRESH_TIME:
                 updateTimes();