在firebase项目中添加了所需的行之后，我在尝试同步android studio项目时遇到了这个错误。只是，这是一个常见的android工作室项目，我只想在其中应用firebase数据库。拜托，如果有人知道会发生什么事？谢谢。
pd:我已经在其他stackoverflow问题上搜索了这个错误，但是没有一个答案对我有效：(
这是我的版本。gradle（项目）：

// Top-level build file where you can add configuration options common to all sub-projects/modules.

buildscript {
    repositories {
        google()
        jcenter()

    }
    dependencies {
        classpath 'com.android.tools.build:gradle:3.4.1'
        classpath 'com.google.gms:google-services:4.3.4'
        //classpath 'com.google.firebase:firebase-crashlytics-gradle:2.2.1'

        // NOTE: Do not place your application dependencies here; they belong
        // in the individual module build.gradle files
    }
}

allprojects {
    repositories {
        google()
        jcenter()

    }
}

task clean(type: Delete) {
    delete rootProject.buildDir
}

以及我的buid.gradle（应用程序）：

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

android {
    compileSdkVersion 28
    buildToolsVersion "29.0.0"
    defaultConfig {
        applicationId "com.example.proceedingmanager"
        minSdkVersion 21
        targetSdkVersion 28
        versionCode 1
        versionName "1.0"
        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
        }
    }
}

dependencies {
    implementation fileTree(dir: 'libs', include: ['*.jar'])
    implementation 'com.android.support:appcompat-v7:28.0.0'
    implementation 'com.android.support.constraint:constraint-layout:2.0.4'
    testImplementation 'junit:junit:4.12'
    androidTestImplementation 'com.android.support.test:runner:1.0.2'
    androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.2'

    implementation platform('com.google.firebase:firebase-bom:26.2.0')
    implementation 'com.google.firebase:firebase-analytics'
}