java.lang.RuntimeException: Duplicate class android.support.v4.os.ResultReceiver found in modules jetified-androidx.core.core-1.2.0-runtime.jar (:androidx.core.core-1.2.0:) and jetified-support-compat-27.1.1-runtime.jar (:support-compat-27.1.1:)

android.useAndroidX=true
android.enableJetifier=true

org.gradle.jvmargs=-Xmx**JVM_HEAP_SIZE**M
org.gradle.parallel=true
android.enableR8=**MINIFY_WITH_R_EIGHT**
android.useAndroidX=true
android.enableJetifier=true

using System.Collections;
using System.Threading.Tasks;
using UnityEngine;
using UnityEngine.Events;
using Firebase;
using Firebase.Extensions;
using Firebase.Database;

public class FirebaseInit : MonoBehaviour
{
    public static FirebaseInit instance;
    public UnityEvent OnFirebaseInit = new UnityEvent();
    [HideInInspector] public static bool initialized = false;

    Firebase.FirebaseApp app;
    private FirebaseDatabase _db;
    public ARTargets arTargets = null;
    private string dataReferenceString = "cxrave";

    private void Start()
    {
        instance = this;
        Firebase.FirebaseApp.CheckAndFixDependenciesAsync().ContinueWithOnMainThread(task =>
        {

            if (task.Exception != null)
            {
                Debug.LogError(System.String.Format(
                   "Could not resolve all Firebase dependencies: {0}", task.Exception));
                return;
            }

            OnFirebaseInit.Invoke();
            initialized = true;
            _db = FirebaseDatabase.DefaultInstance;
            // listen for future data updates
            _db.GetReference(dataReferenceString).ValueChanged  = HandleValueChanged;

        });

    }

    private void LoadARTargetData()
    {
        _db.GetReference(dataReferenceString).GetValueAsync().ContinueWith(task =>
        {
            if (task.IsFaulted)
                Debug.LogError("task faulted"   task.Exception);
            else if (task.IsCompleted)
            {
                DataSnapshot rawData = task.Result;
                arTargets = JsonUtility.FromJson<ARTargets>(rawData.GetRawJsonValue());
            }
        });
    }

    void HandleValueChanged(object sender, ValueChangedEventArgs args)
    {
        if (args.DatabaseError != null)
        {
            Debug.LogError(args.DatabaseError.Message);
            return;
        }
        // Do something with the data in args.Snapshot
        var data = args.Snapshot.GetRawJsonValue();
        arTargets = JsonUtility.FromJson<ARTargets>(data);
        // send update to target manager to add targets to the scene
        TargetManager.HandleDataUpdate(arTargets);
    }

}