Don't clear data summary when loader is cancelled

Keep whatever summary we had before.

Bug: 22351861
Change-Id: Id2088404f09dcadce1cbf2959918956844d613a7

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

@@ -937,8 +937,7 @@ public class InstalledAppDetails extends AppInfoBase
 
         @Override
         public void onLoaderReset(Loader<ChartData> loader) {
-            mChartData = null;
-            mDataPreference.setSummary(getDataSummary());
+            // Leave last result.
         }
     };