Refresh Storage UI atomically.

Test: builds
Bug: 29275971
Change-Id: I0f5131631ae12bc57e66545513ad60b7cbcd179b

src/com/android/settings/deviceinfo/StorageSettings.java

@@ -152,7 +152,7 @@ public class StorageSettings extends SettingsPreferenceFragment implements Index
         }
     }
 
-    private void refresh() {
+    private synchronized void refresh() {
         final Context context = getPrefContext();
 
         getPreferenceScreen().removeAll();