Gradle sync failed: Version: 8.4.0 is lower than the minimum version (9.0.0) required for google-services plugin
<p>I'm trying to integrate Google's Firebase SDK as explained <a href="https://firebase.google.com/docs/android/setup">here</a></p>

<p>But I'm getting this error when I try to build the project:</p>

<p><code>Gradle sync failed: Version: 8.4.0 is lower than the minimum version (9.0.0) required for google-services plugin.</code></p>

<p>This is my project's <code>build.gradle</code> file :</p>

<pre><code>buildscript {
    repositories {
        jcenter()
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:2.1.0'
        classpath 'com.google.gms:google-services:3.0.0'
    }
}

allprojects {
    repositories {
        jcenter()
    }
}
</code></pre>

<p>and this is app's <code>build.gradle</code> file:</p>

<pre><code>buildscript {
    repositories {
        maven { url 'https://maven.fabric.io/public' }
    }
    dependencies {
        classpath 'io.fabric.tools:gradle:1.+'
    }
}
apply plugin: 'com.android.application'
apply plugin: 'io.fabric'

repositories {
    maven { url 'https://maven.fabric.io/public' }
}
android {
    lintOptions {
        abortOnError false
    }
    signingConfigs {
        release {
        }
    }
    compileSdkVersion Integer.parseInt(project.COMPILE_SDK_VERSION)
    buildToolsVersion project.BUILD_TOOLS_VERSION
    defaultConfig {
        applicationId 'club.androidy.callcontrolfree'
        minSdkVersion project.MIN_SDK
        targetSdkVersion project.TARGET_SDK_VERSION
        versionName project.VERSION_NAME
        versionCode Integer.parseInt(project.VERSION_CODE)
    }
    buildTypes {
        release {
            minifyEnabled true
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.txt'
            signingConfig signingConfigs.release
        }
    }
    productFlavors {
    }
}

dependencies {
    compile fileTree(include: ['*.jar'], dir: 'libs')
    compile 'com.google.android.gms:play-services-ads:8.4.0'
    compile 'com.google.android.gms:play-services-analytics:8.4.0'
    compile 'com.android.support:support-v4:23.3.0'
    compile 'com.android.support:design:23.3.0'
    compile('com.crashlytics.sdk.android:crashlytics:2.5.5@aar') {
        transitive = true;
    }
    compile 'com.android.support:cardview-v7:23.3.0'
    compile 'com.google.firebase:firebase-core:9.0.0'
    compile 'com.google.firebase:firebase-crash:9.0.0'
}
apply plugin: 'com.google.gms.google-services'
</code></pre>

<p>What's wrong here?</p>

<p>Thanks in advance.</p>