title: how to create extensible choice parameter groovy script in dsl?
body: <p>how to create extensible choice parameter groovy script in dsl?</p>
  
  <p>I have manually created Entensible choice parameter with following properties</p>
  
  <p>Name: env<br>
  Choice provider: System Groovy Choice Parameter<br>
  Groovy Script: //script here<br></p>
  
  <p><a href="https://i.stack.imgur.com/CuHC3.png" rel="nofollow noreferrer">Click here for Extensible choice parameter image</a></p>
  
  <p>I need this to be scripted in freeStyleJob dsl</p>