title: Uncheck Dropdown Item at Runtime in Unity
body: <p>This seems trivial but I'm having difficulty. </p>
  
  <p>A user selects an item in a dropdown and this creates a little checkmark next to the item. </p>
  
  <p>I want to deselect it in my code and remove that checkmark.</p>
  
  <p>Any ideas?</p>