Java FCM发送通知Firebase不通过PHP显示前台

manifest.xml

<manifest
    xmlns:android="http://schemas.android.com/apk/res/android"
    package="im.delight.android.examples.webview"
    android:versionCode="1"
    android:versionName="1.0">

    <uses-permission android:name="android.permission.INTERNET" />
    <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
    <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="Label"
        android:theme="@style/AppTheme">
        <activity
            android:name=".MainActivity"
            android:launchMode="singleTask"
            android:label="Label">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
            <intent-filter>
                <action android:name=".MainActivity" />
                <category android:name="android.intent.category.DEFAULT" />
            </intent-filter>
        </activity>
    </application>
</manifest>


part of mainactivity.java

package im.delight.android.examples.webview;

import im.delight.android.webview.AdvancedWebView;
import android.webkit.WebChromeClient;
import android.widget.Toast;
import android.webkit.WebView;
import android.view.View;
import android.webkit.WebViewClient;
import android.graphics.Bitmap;
import android.content.Intent;
import android.annotation.SuppressLint;
import android.os.Bundle;
import android.app.Activity;
import com.google.android.gms.tasks.OnCompleteListener;
import com.google.android.gms.tasks.Task;
import androidx.annotation.NonNull;
import android.util.Log;
import com.google.android.gms.tasks.OnCompleteListener;
import com.google.android.gms.tasks.Task;
import com.google.firebase.iid.FirebaseInstanceId;
import com.google.firebase.iid.InstanceIdResult;

public class MainActivity extends Activity implements AdvancedWebView.Listener {

    private static final String TAG = "MainActivity"; String TEST_PAGE_URL = "https://example.com";
    private AdvancedWebView mWebView;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
         Bundle bundle = getIntent().getExtras();
            if (bundle != null) {
               //bundle must contain all info sent in "data" field of the notification
            }
        mWebView = (AdvancedWebView) findViewById(R.id.webview);
        mWebView.setListener(this, this);
        mWebView.setGeolocationEnabled(false);
        mWebView.setMixedContentAllowed(false);
        mWebView.setCookiesEnabled(true);
        mWebView.setThirdPartyCookiesEnabled(true);
        mWebView.setWebViewClient(new WebViewClient() {

            @Override
            public void onPageFinished(WebView view, String url) {
                Toast.makeText(MainActivity.this, "Se încarcă...", Toast.LENGTH_SHORT).show();

            }


        });


        mWebView.setWebChromeClient(new WebChromeClient() {

            @Override
            public void onReceivedTitle(WebView view, String title) {
                super.onReceivedTitle(view, title);
                Toast.makeText(MainActivity.this, title, Toast.LENGTH_SHORT).show();
            }

        });

        FirebaseInstanceId.getInstance().getInstanceId()
                .addOnCompleteListener(new OnCompleteListener<InstanceIdResult>() {
                    @Override
                    public void onComplete(@NonNull Task<InstanceIdResult> task) {
                        if (!task.isSuccessful()) {
//To do//
                            return;
                        }

                         String token = task.getResult().getToken();
                        String msg = getString(R.string.fcm_token, token);
                        String str= msg;
                        final String yeh = (str.substring(11));
                        Log.d(TAG, msg);

PHP

当应用程序在后台/未运行时工作正常，但当应用程序在前台运行时，它不会显示通知

我做错了什么？我尝试使用消息，但我需要刷新应用程序（先放在后台，然后放在前台），以便消息出现

请帮忙

apply plugin: 'com.android.application'
apply plugin: 'com.google.gms.google-services'
android {
    compileSdkVersion 28
    buildToolsVersion '27.0.3'

    defaultConfig {
        applicationId "com.domain.com"
        minSdkVersion 16
        targetSdkVersion 21
        multiDexEnabled true

    }


    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.txt'
        }
    }
}

dependencies {
    compile project(':library')
    implementation 'com.android.support:multidex:1.0.3'
    implementation 'com.google.firebase:firebase-analytics:17.5.0'
    implementation 'com.google.firebase:firebase-storage-ktx:19.2.0'
    implementation 'com.google.firebase:firebase-messaging-ktx:20.3.0'
    implementation 'com.android.support:appcompat-v7:28.0.0'
    androidTestImplementation "com.android.support:support-annotations:28.0.0"
    implementation 'com.google.firebase:firebase-inappmessaging-display-ktx:19.1.1'


}

define( 'API_ACCESS_KEY', 'x');        
// target device 'fcm' id
$device[0]='x';

    $url = 'https://fcm.googleapis.com/fcm/send';

    $data = array("registration_ids" => $device,            
        "notification" => array( 
        "title" => "text", 
        "body" => "text",
        'icon'=>'url',
        "sound" => "default"
    ),
        "data"=>array(
        "name"=>"xyz",
        'image'=>'uurl'
        )
    ); 

    $data_string = json_encode($data); 
    $headers = array ( 'Authorization: key=' . API_ACCESS_KEY, 'Content-Type: application/json' ); 
    $ch = curl_init(); 
    curl_setopt( $ch,CURLOPT_URL,$url ); 
    curl_setopt( $ch,CURLOPT_POST, true ); 
    curl_setopt( $ch,CURLOPT_HTTPHEADER, $headers ); 
    curl_setopt( $ch,CURLOPT_RETURNTRANSFER, true ); 
    curl_setopt( $ch,CURLOPT_POSTFIELDS, $data_string); 
    $result = curl_exec($ch);