title: How to remove button shadow (android)
body: <p>I want to remove the shadow from the button to make it seem more flat.</p>
  
  <p>I have this right now: </p>
  
  <p><img src="https://i.stack.imgur.com/ANKfF.png" alt="cancel button with shadow"></p>
  
  <p>But I want this: </p>
  
  <p><img src="https://i.stack.imgur.com/jZfWz.png" alt="cancel button without shadow"></p>