title: Material Design Datepicker: How to popup datepicker when click on a Spinner
body: <p>I am looking to follow the material design guidelines on having a spinner like this:
  <a href="https://i.stack.imgur.com/sF78B.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/sF78B.png" alt="enter image description here"></a></p>
  
  <p>And when clicked it should pupup a DatePickerDialog like this:</p>
  
  <p><a href="https://i.stack.imgur.com/fqgo5.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/fqgo5.png" alt="enter image description here"></a></p>
  
  <p>And finally when date chosen, get the chosen date inside the spinner like this:
  <a href="https://i.stack.imgur.com/Qh04z.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/Qh04z.png" alt="enter image description here"></a></p>
  
  <p>I need help with how do I declare such a spinner in xml?</p>