Add back the data saver preference.

Bug: 70950124

Test: manual
Test: make RunSettingsRoboTests
Change-Id: Ia39cb62ec021ae568a76fed04776b5e531e63b36

src/com/android/settings/datausage/DataUsageSummary.java

@@ -261,7 +261,10 @@ public class DataUsageSummary extends DataUsageBaseFragment implements Indexable
     private void updateState() {
         PreferenceScreen screen = getPreferenceScreen();
         for (int i = 1; i < screen.getPreferenceCount(); i++) {
-            ((TemplatePreferenceCategory) screen.getPreference(i)).pushTemplates(services);
+          Preference currentPreference = screen.getPreference(i);
+          if (currentPreference instanceof TemplatePreferenceCategory) {
+            ((TemplatePreferenceCategory) currentPreference).pushTemplates(services);
+          }
         }
     }