Eliminate duplicate keys in pref xmls.

- Remove additional_system_update pref device_info page, we don't need
  it.
- Update keys in xml and Preference controller, and search index
  provider.
- Clean up in ScreenZoomPreference, it's anti-pattern to set fragment in
  constructor.
- Whitelist 2 that are super hard to remove.

Change-Id: Ibab6e2cb074513042a2ae007d9085aa64046eec8
Fixes: 67852637
Test: uniquePreferenceTest

src/com/android/settings/DeviceInfoSettings.java

@@ -26,7 +26,6 @@ import android.util.FeatureFlagUtils;
 import com.android.internal.logging.nano.MetricsProto.MetricsEvent;
 import com.android.settings.dashboard.DashboardFragment;
 import com.android.settings.dashboard.SummaryLoader;
-import com.android.settings.deviceinfo.AdditionalSystemUpdatePreferenceController;
 import com.android.settings.deviceinfo.BasebandVersionPreferenceController;
 import com.android.settings.deviceinfo.BuildNumberPreferenceController;
 import com.android.settings.deviceinfo.DeviceModelPreferenceController;
@@ -153,7 +152,6 @@ public class DeviceInfoSettings extends DashboardFragment implements Indexable {
         final List<AbstractPreferenceController> controllers = new ArrayList<>();
         controllers.add(
                 new BuildNumberPreferenceController(context, activity, fragment, lifecycle));
-        controllers.add(new AdditionalSystemUpdatePreferenceController(context));
         controllers.add(new ManualPreferenceController(context));
         controllers.add(new FeedbackPreferenceController(fragment, context));
         controllers.add(new KernelVersionPreferenceController(context));