Fix storage title clearing in multi-window

By accurately tracking detached state.

Change-Id: If9d60000f7737c834afde680d15a2af21f7e3165
Fixes: 27989238

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

@@ -325,6 +325,12 @@ public class PrivateVolumeSettings extends SettingsPreferenceFragment {
         mStorageManager.unregisterListener(mStorageListener);
     }
 
+    @Override
+    public void onAttach(Context context) {
+        super.onAttach(context);
+        mDetached = false;
+    }
+
     @Override
     public void onDetach() {
         super.onDetach();