Dark theme settings activity

Dark theme settings is now launchable as an activity

Test: launch activity android.settings.DARK_THEME_SETTINGS
Fixes: 145560830

Change-Id: I24b8d3211e9d6e7a5b1f226001882573ae7fb311
diff --git a/src/com/android/settings/Settings.java b/src/com/android/settings/Settings.java
index ab59da4..e63edd7 100644
--- a/src/com/android/settings/Settings.java
+++ b/src/com/android/settings/Settings.java
@@ -52,6 +52,7 @@
     public static class LocalePickerActivity extends SettingsActivity { /* empty */ }
     public static class LanguageAndInputSettingsActivity extends SettingsActivity { /* empty */ }
     public static class UserDictionarySettingsActivity extends SettingsActivity { /* empty */ }
+    public static class DarkThemeSettingsActivity extends SettingsActivity { /* empty */ }
     public static class DisplaySettingsActivity extends SettingsActivity { /* empty */ }
     public static class NightDisplaySettingsActivity extends SettingsActivity { /* empty */ }
     public static class NightDisplaySuggestionActivity extends NightDisplaySettingsActivity { /* empty */ }
diff --git a/src/com/android/settings/core/gateway/SettingsGateway.java b/src/com/android/settings/core/gateway/SettingsGateway.java
index 384f262..fd03697 100644
--- a/src/com/android/settings/core/gateway/SettingsGateway.java
+++ b/src/com/android/settings/core/gateway/SettingsGateway.java
@@ -74,6 +74,7 @@
 import com.android.settings.deviceinfo.firmwareversion.FirmwareVersionSettings;
 import com.android.settings.deviceinfo.legal.ModuleLicensesDashboard;
 import com.android.settings.display.NightDisplaySettings;
+import com.android.settings.display.darkmode.DarkModeSettingsFragment;
 import com.android.settings.dream.DreamSettings;
 import com.android.settings.enterprise.EnterprisePrivacySettings;
 import com.android.settings.fuelgauge.AdvancedPowerUsageDetail;
@@ -281,7 +282,8 @@
             PreviouslyConnectedDeviceDashboardFragment.class.getName(),
             BatterySaverScheduleSettings.class.getName(),
             MobileNetworkListFragment.class.getName(),
-            GlobalActionsPanelSettings.class.getName()
+            GlobalActionsPanelSettings.class.getName(),
+            DarkModeSettingsFragment.class.getName()
     };
 
     public static final String[] SETTINGS_FOR_RESTRICTED = {