build.gradle

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

buildscript {
    repositories {
        maven { url 'https://maven.google.com' }
        jcenter()
    }
    dependencies {
        File localFile = project.rootProject.file('local.properties')
        Properties extProperties = new Properties()
        if (localFile.exists()) {
            extProperties.load(localFile.newDataInputStream())
        }
        def androidGradlePluginVersion = "3.0.1"
        if (extProperties.containsKey('gradleVersion')) {
            androidGradlePluginVersion = extProperties.get("gradleVersion") as String
        }
        project.logger.error "root build.gradle androidGradlePluginVersion ${androidGradlePluginVersion}"

        classpath "com.android.tools.build:gradle:${androidGradlePluginVersion}"
    }
}

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

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