In ApnEditor, restore preference values after re-creating.

After destroying and re-creating, the preference values in ApnEditor
are not restored. This results in incorrect behavior if it enters
two window mode where it's destroyed and re-created. The fix is to
have them restored and shown correctly.

Bug: 65338066
Test: Manual
Change-Id: I5ea16ce01c72061ab116f9c15bfc5cc39bb7a095

src/com/android/settings/ApnEditor.java

@@ -297,6 +297,11 @@ public class ApnEditor extends SettingsPreferenceFragment
             getPreferenceScreen().getPreference(i).setOnPreferenceChangeListener(this);
         }
 
+    }
+
+    @Override
+    public void onActivityCreated(Bundle savedInstanceState) {
+        super.onActivityCreated(savedInstanceState);
         fillUi();
     }