Align dark theme in accessibility page with the dark theme in display page.

Root Cause: Two different behaved dark theme exist in different page

Solution: Align with the dark theme in display page

Bug: 185880142
Test: manual test
Change-Id: If905c1e3e067377a835223d5d5eb2ca426673e49
diff --git a/res/xml/accessibility_settings.xml b/res/xml/accessibility_settings.xml
index 6fa8b00..267045b 100644
--- a/res/xml/accessibility_settings.xml
+++ b/res/xml/accessibility_settings.xml
@@ -53,11 +53,13 @@
             settings:controller="com.android.settings.accessibility.ReduceBrightColorsPreferenceController"
             settings:keywords="@string/keywords_reduce_bright_colors"/>
 
-        <SwitchPreference
+        <com.android.settings.display.darkmode.DarkModePreference
             android:key="dark_ui_mode_accessibility"
             android:icon="@drawable/ic_dark_ui"
-            android:persistent="false"
             android:title="@string/dark_ui_mode"
+            android:fragment="com.android.settings.display.darkmode.DarkModeSettingsFragment"
+            android:widgetLayout="@null"
+            settings:widgetLayout="@null"
             settings:controller="com.android.settings.display.DarkUIPreferenceController"
             settings:searchable="false"/>