title: Azure DevOps Release Pipeline - Dropdown list of custom variable
body: <p>For Azure DevOps Release pipeline, is it possible to create Dropdown list for custom variables?</p>
  
  <p>So for below, if I wish to have dropdown values instead of single text value
  <a href="https://i.stack.imgur.com/gdd3S.png" rel="noreferrer"><img src="https://i.stack.imgur.com/gdd3S.png" alt="enter image description here"></a></p>