Fix bug #13167668 stability-sys: Java crash in com.android.settings:

...java.lang.RuntimeException: Unable to destroy activity {com.android.settings/
com.android.settings.Settings}: java.lang.IllegalStateException:
Can not perform this action after onSaveInstanceState

- revert the change that was done by

https://googleplex-android-review.git.corp.google.com/#/c/148273/2

Also the OnItemClickListener has been changed since that time to cope
with the initial issue.

Change-Id: I0e3a44e6340f5576bb0f46d5a6c6a5824a44b406

src/com/android/settings/DataUsageSummary.java

@@ -573,11 +573,6 @@ public class DataUsageSummary extends Fragment {
 
         TrafficStats.closeQuietly(mStatsSession);
 
-        if (this.isRemoving()) {
-            getFragmentManager()
-                    .popBackStack(TAG_APP_DETAILS, FragmentManager.POP_BACK_STACK_INCLUSIVE);
-        }
-
         super.onDestroy();
     }