title: Elevation on pre-L devices?
body: <p>I've noticed that <code>elevation</code> is part of the v7 support library.</p>
  
  <p>When applying it to buttons through styles.xml, I don't see any elevation being applied.</p>
  
  <p>Is it supposed to work on pre-L devices? If not, why is it present in the support library ?</p>