Уведомление не отображается при отправке FCM из PHP

Question

Я пытаюсь отправить уведомление с помощью FCM из моего веб-приложения. Однако приложение Android не отображает уведомление. Когда я использую консоль Firebase, появляется уведомление, но когда я использую свой скрипт PHP, это не так. Я провел небольшое исследование и обнаружил, что мое приложение действительно получает полезную нагрузку, но не отображает уведомление. Я пытался найти ошибку, но не могу ее найти. Вот мой код:

MyFirebaseMessagingService

import android.content.Intent;
import android.util.Log;

import com.bloodconnect.Activities.Home;
import com.bloodconnect.Activities.Login;
import com.bloodconnect.FCM.Notification.MyNotificationManager;
import com.google.firebase.messaging.FirebaseMessagingService;
import com.google.firebase.messaging.RemoteMessage;

import org.json.JSONException;
import org.json.JSONObject;

/**
 * Created by delaroy on 10/8/17.
 */

public class MyFirebaseMessagingService extends FirebaseMessagingService {

    private static final String TAG = "MyFirebaseMsgService";

    @Override
    public void onMessageReceived(RemoteMessage remoteMessage) {
        if (remoteMessage.getData().size() > 0) {
            Log.e(TAG, "Data Payload: " + remoteMessage.getData().toString());
            try {
                JSONObject json = new JSONObject(remoteMessage.getData().toString());
                sendPushNotification(json);
            } catch (Exception e) {
                Log.e(TAG, "Exception: " + e.getMessage());
            }
        }
    }

    //this method will display the notification
    //We are passing the JSONObject that is received from
    //firebase cloud messaging
    private void sendPushNotification(JSONObject json) {
        //optionally we can display the json into log
        Log.e(TAG, "Notification JSON " + json.toString());
        try {
            //getting the json data
            JSONObject data = json.getJSONObject("data");

            //parsing json data
            String title = data.getString("title");
            String message = data.getString("message");
            String imageUrl = data.getString("image");

            //creating MyNotificationManager object
            MyNotificationManager mNotificationManager = new MyNotificationManager(getApplicationContext());

            //creating an intent for the notification
            Intent intent = new Intent(getApplicationContext(), Home.class);

            //if there is no image
            if(imageUrl.equals("null")){
                //displaying small notification
                mNotificationManager.showSmallNotification(title, message, intent);
            }else{
                //if there is an image
                //displaying a big notification
                mNotificationManager.showBigNotification(title, message, imageUrl, intent);
            }
        } catch (JSONException e) {
            Log.e(TAG, "Json Exception: " + e.getMessage());
        } catch (Exception e) {
            Log.e(TAG, "Exception: " + e.getMessage());
        }
    }

}

Я отображаю уведомление, используя класс уведомлений.

MyNotificationManager.java

import android.app.Notification;
import android.app.NotificationManager;
import android.app.PendingIntent;
import android.content.Context;
import android.content.Intent;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.support.v4.app.NotificationCompat;
import android.text.Html;

import com.bloodconnect.R;

import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL;

/**
 * Created by delaroy on 10/8/17.
 */

public class MyNotificationManager {

    public static final int ID_BIG_NOTIFICATION = 234;
    public static final int ID_SMALL_NOTIFICATION = 235;

    private Context mCtx;

    public MyNotificationManager(Context mCtx) {
        this.mCtx = mCtx;
    }

    //the method will show a big notification with an image
    //parameters are title for message title, message for message text, url of the big image and an intent that will open
    //when you will tap on the notification
    public void showBigNotification(String title, String message, String url, Intent intent) {
        PendingIntent resultPendingIntent =
                PendingIntent.getActivity(
                        mCtx,
                        ID_BIG_NOTIFICATION,
                        intent,
                        PendingIntent.FLAG_UPDATE_CURRENT
                );
        NotificationCompat.BigPictureStyle bigPictureStyle = new NotificationCompat.BigPictureStyle();
        bigPictureStyle.setBigContentTitle(title);
        bigPictureStyle.setSummaryText(Html.fromHtml(message).toString());
        bigPictureStyle.bigPicture(getBitmapFromURL(url));
        NotificationCompat.Builder mBuilder = new NotificationCompat.Builder(mCtx);
        Notification notification;
        notification = mBuilder.setSmallIcon(R.mipmap.ic_launcher).setTicker(title).setWhen(0)
                .setAutoCancel(true)
                .setContentIntent(resultPendingIntent)
                .setContentTitle(title)
                .setStyle(bigPictureStyle)
                .setSmallIcon(R.mipmap.ic_launcher)
                .setLargeIcon(BitmapFactory.decodeResource(mCtx.getResources(), R.mipmap.ic_launcher))
                .setContentText(message)
                .build();

        notification.flags |= Notification.FLAG_AUTO_CANCEL;

        NotificationManager notificationManager = (NotificationManager) mCtx.getSystemService(Context.NOTIFICATION_SERVICE);
        notificationManager.notify(ID_BIG_NOTIFICATION, notification);
    }

    //the method will show a small notification
    //parameters are title for message title, a message for message text and an intent that will open
    //when you will tap on the notification
    public void showSmallNotification(String title, String message, Intent intent) {
        PendingIntent resultPendingIntent =
                PendingIntent.getActivity(
                        mCtx,
                        ID_SMALL_NOTIFICATION,
                        intent,
                        PendingIntent.FLAG_UPDATE_CURRENT
                );


        NotificationCompat.Builder mBuilder = new NotificationCompat.Builder(mCtx);
        Notification notification;
        notification = mBuilder.setSmallIcon(R.mipmap.ic_launcher).setTicker(title).setWhen(0)
                .setAutoCancel(true)
                .setContentIntent(resultPendingIntent)
                .setContentTitle(title)
                .setSmallIcon(R.mipmap.ic_launcher)
                .setLargeIcon(BitmapFactory.decodeResource(mCtx.getResources(), R.mipmap.ic_launcher))
                .setContentText(message)
                .build();

        notification.flags |= Notification.FLAG_AUTO_CANCEL;

        NotificationManager notificationManager = (NotificationManager) mCtx.getSystemService(Context.NOTIFICATION_SERVICE);
        notificationManager.notify(ID_SMALL_NOTIFICATION, notification);
    }

    //The method will return Bitmap from an image URL
    private Bitmap getBitmapFromURL(String strURL) {
        try {
            URL url = new URL(strURL);
            HttpURLConnection connection = (HttpURLConnection) url.openConnection();
            connection.setDoInput(true);
            connection.connect();
            InputStream input = connection.getInputStream();
            Bitmap myBitmap = BitmapFactory.decodeStream(input);
            return myBitmap;
        } catch (IOException e) {
            e.printStackTrace();
            return null;
        }
    }
}

Мои данные в следующем формате:

Data Payload: {data={"image":null,"title":"Test123","message":"test123"}}

Я совершенно не могу понять, почему уведомление не отображается. Если бы кто-то мог помочь, это было бы очень полезно.