title: Gradle task should not execute automatically
body: <p>I'm defining a task in gradle:</p>
  
  <pre><code>task releaseCandidate(type: Exec) {
      commandLine 'git', 'checkout', 'develop'
  
      // Increment version code in Manifest
      String manifest = new File('AndroidManifest.xml').getText('UTF-8')
      Pattern pattern = Pattern.compile('android:versionCode="([0-9]+)"')
      Matcher matcher = pattern.matcher(manifest)
      matcher.find()
      int newVersionCode = Integer.parseInt(matcher.group(1)) + 1
      manifest = manifest.replaceAll(
          "android:versionCode=\"([0-9]+)\"", "android:versionCode=\"$newVersionCode\""
      )
      new File('AndroidManifest.xml').write(manifest, 'UTF-8')
  
      commandLine 'git', 'diff'
  }
  </code></pre>
  
  <p>Which I want to execute only when I explicitly call it as <code>gradle releaseCandidate</code>. <strong>However, when I run any other task, such as <code>gradle assembleDebug</code>, it also runs task releaseCandidate.</strong> I don't want that behaviour to happen. There is no task depending on releaseCandidate or vice-versa. </p>
  
  <p>My project is an Android app, so I am using <code>android</code> gradle plugin.</p>