Difference between using androidx.preference.PreferenceScreen and PreferenceScreen

My app targets API 28 and has a minimum API 15. As support library, I'm using AndroidX.
I have a preference fragment hosted by an activity, like this:

SettingsFragment.java

package com.example.app;

import android.os.Bundle;

import androidx.preference.PreferenceFragmentCompat;

public class SettingsFragment extends PreferenceFragmentCompat {

    @Override
    public void onCreatePreferences(Bundle savedInstanceState, String rootKey) {
        setPreferencesFromResource(R.xml.preferences, rootKey);

    }
}

SettingsActivity.java

package com.example.app;

import android.os.Bundle;

import androidx.appcompat.app.AppCompatActivity;

public class SettingsActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        getSupportFragmentManager().beginTransaction().replace(android.R.id.content, new SettingsFragment()).commit();
    }
}

And here is the XML layout used by SettingsFragment.java

preferences.xml

<?xml version="1.0" encoding="utf-8"?>
<PreferenceScreen xmlns:android="http://schemas.android.com/apk/res/android">
    <SwitchPreference
        android:defaultValue="false"
        android:key="pref_switch"
        android:title="@string/switch" />
</PreferenceScreen>

As the root of the preference hierarchy, should I use PreferenceScreen or androidx.preference.PreferenceScreen for the layout to actually be backward compatible (using AndroidX)? What is the difference between the two? What is the best practice?