android studio 编译打包 出现Could not download xxx.jar解决方案

在project 根build.gradle里修改maven代理：

  repositories {
        maven { url 'https://maven.aliyun.com/repository/public' }
        maven { url 'https://jitpack.io' }
        maven { url 'https://maven.aliyun.com/repository/google' }
    }