Android 当收到firebase的通知时，应用程序不断崩溃

我正在尝试使用Firebase消息为我的应用程序添加通知。我正在使用firebase云消息发送通知。我还使用云函数来设置对用户的通知。我现在遇到的问题是，只要是关于接收通知的应用程序，它就会崩溃

这是我的身材，格雷德尔

def localProperties = new Properties()
def localPropertiesFile = rootProject.file('local.properties')
if (localPropertiesFile.exists()) {
    localPropertiesFile.withReader('UTF-8') { reader ->
        localProperties.load(reader)
    }
}

def flutterRoot = localProperties.getProperty('flutter.sdk')
if (flutterRoot == null) {
    throw new GradleException("Flutter SDK not found. Define location with flutter.sdk in the local.properties file.")
}

def flutterVersionCode = localProperties.getProperty('flutter.versionCode')
if (flutterVersionCode == null) {
    flutterVersionCode = '1'
}

def flutterVersionName = localProperties.getProperty('flutter.versionName')
if (flutterVersionName == null) {
    flutterVersionName = '1.0'
}

apply plugin: 'com.android.application'
apply from: "$flutterRoot/packages/flutter_tools/gradle/flutter.gradle"


android {
    compileSdkVersion 29

    lintOptions {
        disable 'InvalidPackage'
    }

    defaultConfig {
        // TODO: Specify your own unique Application ID (https://developer.android.com/studio/build/application-id.html).
        applicationId "com.example.wall"
        minSdkVersion 16
        multiDexEnabled true
        targetSdkVersion 29
        versionCode flutterVersionCode.toInteger()
        versionName flutterVersionName
    }

    buildTypes {
        release {
            // TODO: Add your own signing config for the release build.
            // Signing with the debug keys for now, so `flutter run --release` works.
            signingConfig signingConfigs.debug
        }
    }
}

flutter {
    source '../..'
}

apply plugin: 'com.google.gms.google-services'

这是我的云功能

const functions = require("firebase-functions");
const admin = require("firebase-admin");
admin.initializeApp();




exports.onCreateActivityFeedItem = functions.firestore
.document('/feed/{userId}/feedItems/{activityFeedItem}')
.onCreate(async (snapshot, context) =>
{
    const userId = context.params.userId;
    const userRef = admin.firestore().doc(`users/${userId}`);
    const doc = await userRef.get();


    const androidNotificationToken = doc.data().androidNotificationToken;
    const createActivityFeedItem = snapshot.data();

    if(androidNotificationToken)
    {
        sendNotification(androidNotificationToken, createActivityFeedItem);
    }
    else
    {
        console.log("No token for user, can not send notification.")
    }

    function sendNotification(androidNotificationToken, activityFeedItem)
    {
        let body;

        switch (activityFeedItem.type)
        {
            case "comment":
                body = `${activityFeedItem.username} replied: ${activityFeedItem.commentData}`;
                break;

            case "like":
                body = `${activityFeedItem.username} liked your post`;
                break;

            case "follow":
                body = `${activityFeedItem.username} started following you`;
                break;

            default:
            break;
        }

        const message =
        {
            notification: { body },
            token: androidNotificationToken,
            data: { recipient: userId },
        };

        admin.messaging().send(message)
        .then(response =>
        {
            console.log("Successfully sent message", response);
        })
        .catch(error =>
        {
            console.log("Error sending message", error);
        })

    }
});

感谢您的帮助。多谢各位