Recheck the storage sizes when Storage settings is resumed.

Bug: 3312629

When the Storage fragment is displayed, invalidate the measurement
object so that it recomputes the used space on all partitions.

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

@@ -217,6 +217,7 @@ public class Memory extends SettingsPreferenceFragment implements OnCancelListen
         intentFilter.addDataScheme("file");
         getActivity().registerReceiver(mReceiver, intentFilter);
 
+        mMeasurement.invalidate();
         if (!Environment.isExternalStorageEmulated()) {
             mMeasurement.measureExternal();
         }