Settings: Use new API for setting wifi scan always on

Bug: 148514485
Test: Manually verified the toggle from Settings
Test: m RunSettingsRoboTests -j ROBOTEST_FILTER=com.android.settings.wifi
Change-Id: I0a55b7212c97c11d50b0a05eec743e8ebe9ea6d8

src/com/android/settings/wifi/WifiScanModeActivity.java

@@ -24,7 +24,6 @@ import android.content.pm.ApplicationInfo;
 import android.content.pm.PackageManager;
 import android.net.wifi.WifiManager;
 import android.os.Bundle;
-import android.provider.Settings;
 import android.text.TextUtils;
 
 import androidx.appcompat.app.AlertDialog;
@@ -80,8 +79,7 @@ public class WifiScanModeActivity extends FragmentActivity {
     }
 
     private void doPositiveClick() {
-        Settings.Global.putInt(getContentResolver(),
-                Settings.Global.WIFI_SCAN_ALWAYS_AVAILABLE, 1);
+        getApplicationContext().getSystemService(WifiManager.class).setScanAlwaysAvailable(true);
         setResult(RESULT_OK);
         finish();
     }