Setting to control UI mode

Fixes: 69783413
Test: tests/robotests/src/com/android/settings/development/DarkUIModePreferenceControllerTest.java
Change-Id: I600036bfb8893f8b1bd93de81c10808bf24998ad
diff --git a/res/xml/development_settings.xml b/res/xml/development_settings.xml
index a88a97b..570f976 100644
--- a/res/xml/development_settings.xml
+++ b/res/xml/development_settings.xml
@@ -112,6 +112,13 @@
             <intent android:action="com.android.settings.action.DEMO_MODE" />
         </Preference>
 
+        <ListPreference
+            android:key="dark_ui_mode"
+            android:title="@string/dark_ui_mode"
+            android:dialogTitle="@string/dark_ui_mode_title"
+            android:entries="@array/dark_ui_mode_entries"
+            android:entryValues="@array/dark_ui_mode_values" />
+
         <Preference
             android:key="quick_settings_tiles"
             android:title="@string/quick_settings_developer_tiles"