title: Declaring custom 'clean' task when using the standard Gradle lifecycle plugins is not allowed
body: <p>I am adding a library to jCenter so to do that I needed to add some plugins to my project's build.gradle file. However, I am getting the error</p>
  
  <blockquote>
    <p>Declaring custom 'clean' task when using the standard Gradle lifecycle plugins is not allowed.</p>
  </blockquote>
  
  <p>I can see the <code>task clean</code> block and when I delete it the error goes away. I assume that is all I need to do, but was it doing something important before? If I remove the plugins sometime and forget to add the <code>clean</code> block back in, what dire consequences are in store?</p>
  
  <pre><code>buildscript {
      repositories {
          jcenter()
      }
      dependencies {
          classpath 'com.android.tools.build:gradle:2.3.1'
  
          // NOTE: Do not place your application dependencies here; they belong
          // in the individual module build.gradle files
      }
  }
  
  plugins {
      id "com.jfrog.bintray" version "1.7.3"
      id "com.github.dcendents.android-maven" version "1.5"
  }
  
  allprojects {
      repositories {
          jcenter()
      }
  }
  
  task clean(type: Delete) {
      delete rootProject.buildDir
  }
  </code></pre>
  
  <p><a href="https://stackoverflow.com/questions/39487387/why-is-there-a-custom-clean-task-in-build-gradle-for-android-projects">This</a> and <a href="https://github.com/palantir/gradle-npm-run-plugin/issues/17" rel="noreferrer">this</a> this did not satisfactorily answer the question.</p>