AndroidStudio3.6的卸载安装，Gradle持续下载/Gradle Build失败等问题

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

buildscript {
  
  repositories {
    maven { url 'http://maven.aliyun.com/nexus/content/groups/public/' }
    maven{ url 'http://maven.aliyun.com/nexus/content/repositories/jcenter'}
    google()
  }
  dependencies {
    classpath 'com.android.tools.build:gradle:3.6.1'
    

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

allprojects {
  repositories {
    maven { url 'http://maven.aliyun.com/nexus/content/groups/public/' }
    maven{ url 'http://maven.aliyun.com/nexus/content/repositories/jcenter'}
    google()
  }
}

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

allprojects{
  repositories {
    def ALIYUN_REPOSITORY_URL = 'http://maven.aliyun.com/nexus/content/groups/public'
    def ALIYUN_JCENTER_URL = 'http://maven.aliyun.com/nexus/content/repositories/jcenter'
    all { ArtifactRepository repo ->
      if(repo instanceof MavenArtifactRepository){
        def url = repo.url.toString()
        if (url.startsWith('https://repo1.maven.org/maven2')) {
          project.logger.lifecycle "Repository ${repo.url} replaced by $ALIYUN_REPOSITORY_URL."
          remove repo
        }
        if (url.startsWith('https://jcenter.bintray.com/')) {
          project.logger.lifecycle "Repository ${repo.url} replaced by $ALIYUN_JCENTER_URL."
          remove repo
        }
      }
    }
    maven {
      url ALIYUN_REPOSITORY_URL
      url ALIYUN_JCENTER_URL
    }
  }
}