title: How to implement new material BottomAppBar as BottomNavigationView
body: <p>I was trying to implement the new BottomAppBar that usually looks like this:
  <a href="https://i.stack.imgur.com/1NfT7.png" rel="noreferrer">material BottomAppBar</a> as a BottomNavigationView like in the Google home app that looks like <a href="https://i.stack.imgur.com/LSUVD.jpg" rel="noreferrer">this</a>.</p>
  
  <p>My problem is that since I can fill the BottomAppBar only with a menu resource, I can't understand how to align my buttons to look like a BottomNavigationView (but with the "cut" for the Fab button) instead of align everything to one side of the BottomAppBar.</p>
  
  <p>How can I add a custom layout inside this new Material BottomAppBar?</p>
  
  <p>Or instead, is there any way to implement a BottomNavigationView with the "cut" for for the Fab button (keeping cool default animations like the new BottomAppBar)?</p>