Fix battery saver number format issue

- The summary of battery saver scheduler use util to convert the number
   but saver sticky preference use another way to convert it, update
   them to use the same convert method

Bug: 250684701
Test: make SettingsRoboTests
Change-Id: I4f188a2e8e9d4810d187b870e331dc84f50b2b6f

src/com/android/settings/fuelgauge/batterysaver/BatterySaverStickyPreferenceController.java

@@ -1,7 +1,6 @@
 package com.android.settings.fuelgauge.batterysaver;
 
 import android.content.Context;
-import android.icu.text.NumberFormat;
 import android.provider.Settings;
 import android.provider.Settings.Global;
 import android.text.TextUtils;
@@ -10,6 +9,7 @@ import androidx.preference.Preference;
 import androidx.preference.SwitchPreference;
 
 import com.android.settings.R;
+import com.android.settings.Utils;
 import com.android.settings.core.PreferenceControllerMixin;
 import com.android.settings.core.TogglePreferenceController;
 
@@ -44,7 +44,7 @@ public class BatterySaverStickyPreferenceController extends TogglePreferenceCont
             mContext.getContentResolver(), Global.LOW_POWER_MODE_STICKY_AUTO_DISABLE_LEVEL, 90);
         preference.setSummary(TextUtils.expandTemplate(
                 mContext.getString(R.string.battery_saver_sticky_description_new),
-                NumberFormat.getIntegerInstance().format(stickyShutoffLevel)));
+                Utils.formatPercentage(stickyShutoffLevel)));
     }
 
     @Override