title: Can't get rid of shadow under Android Button
body: <p>I have a Android Button that I'm placing on my screen, and am defining a custom background drawable that just specifies a green rectangle for now. But, for some reason there appears to be a very thin shadow being drawn under my button (highlighted with the red box):<img src="https://i.stack.imgur.com/gAb2X.png" alt="enter image description here"></p>
  
  <p>Is there any way to get rid of this while still using a Button? It because really ugly when I change my background drawable to have rounded corners.</p>
  
  <p>Thanks!</p>