我正在尝试连接我的应用程序与firebase-console。我按照指示一步一步。但当我按照这一步，
“适用于Gradle的Google服务插件包含您刚下载的google-services.json文件。请更改您的build.grade文件以使用此插件。”
项目级构建。gradle：

buildscript {
      dependencies {
        // Add this line
        classpath 'com.google.gms:google-services:3.1.0'
      }
    }

应用程序级构建.gradle

...
    // Add to the bottom of the file
    apply plugin: 'com.google.gms.google-services'

然后尝试同步，我得到这个错误

Error(31,0) Plugin with id 'com.google.gms.google-play-services' not found

......有人能帮我解决这个问题吗？现在这是我的代码了。
项目生成器.gradle

buildscript {

    repositories {
        google()
        jcenter()
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:3.0.0'
        classpath 'com.google.gms:google-services:3.1.0'

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

allprojects {
    repositories {
        google()
        jcenter()
        maven {
            url "https://maven.google.com"
        }
    }
}

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

应用构建器.gradle

apply plugin: 'com.android.application'

android {
    compileSdkVersion 26
    defaultConfig {
        applicationId "com.example.kreuzell.myapplicationss"
        minSdkVersion 15
        targetSdkVersion 26
        versionCode 1
        versionName "1.0"
        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
}

dependencies {
    implementation fileTree(dir: 'libs', include: ['*.jar'])
    implementation 'com.android.support:appcompat-v7:26.1.0'
    implementation 'com.android.support.constraint:constraint-layout:1.0.2'
    testImplementation 'junit:junit:4.12'
    androidTestImplementation 'com.android.support.test:runner:1.0.1'
    androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.1'
    implementation 'com.google.android.gms:play-services-ads:11.4.2'
}

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