Fix the button display problem in Dark theme page

- Dark theme is disabled when Battery save is on.
- Let dark theme page not be searchable when Battery save is on.

Fixes: 150443799
Test: make RunSettingsRoboTests -j ROBOTEST_FILTER=com.android.settings.display.darkmode
Change-Id: I2674499dd64333825765f70ed1f31dcb83e1b895
diff --git a/src/com/android/settings/display/darkmode/DarkModeSettingsFragment.java b/src/com/android/settings/display/darkmode/DarkModeSettingsFragment.java
index 97ee221..530a541 100644
--- a/src/com/android/settings/display/darkmode/DarkModeSettingsFragment.java
+++ b/src/com/android/settings/display/darkmode/DarkModeSettingsFragment.java
@@ -15,19 +15,19 @@
 package com.android.settings.display.darkmode;
 
 import android.app.Dialog;
-import android.app.TimePickerDialog;
-import android.app.UiModeManager;
+import android.app.settings.SettingsEnums;
 import android.content.Context;
 import android.os.Bundle;
-import android.app.settings.SettingsEnums;
+import android.os.PowerManager;
+
 import androidx.preference.Preference;
+
 import com.android.settings.R;
 import com.android.settings.dashboard.DashboardFragment;
 import com.android.settings.search.BaseSearchIndexProvider;
 import com.android.settingslib.core.AbstractPreferenceController;
 import com.android.settingslib.search.SearchIndexable;
 
-import java.time.LocalTime;
 import java.util.ArrayList;
 import java.util.List;
 
@@ -143,5 +143,11 @@
     }
 
     public static final BaseSearchIndexProvider SEARCH_INDEX_DATA_PROVIDER =
-            new BaseSearchIndexProvider(R.xml.dark_mode_settings);
+            new BaseSearchIndexProvider(R.xml.dark_mode_settings) {
+                @Override
+                protected boolean isPageSearchEnabled(Context context) {
+                    return !context.getSystemService(PowerManager.class).isPowerSaveMode();
+                }
+            };
+
 }