使用阿里云镜像减少gralde 同步时间

在项目gradle文件中配置，将镜像地址配置在google()和jcenter()之前，这样就会先去镜像中查找依赖。

buildscript {
    
    repositories {
        maven {
            url 'https://maven.aliyun.com/repository/jcenter'
        }
        maven {
            url 'https://maven.aliyun.com/repository/central'
        }
        maven {
            url 'https://maven.aliyun.com/repository/google'
        }
        google()
        jcenter()
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:3.1.2'

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

allprojects {
    repositories {
        maven {
            url 'https://maven.aliyun.com/repository/jcenter'
        }
        maven {
            url 'https://maven.aliyun.com/repository/central'
        }
        maven {
            url 'https://maven.aliyun.com/repository/google'
        }

        google()
        jcenter()
    }
}

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