title: Show DrawerLayoutAndroid via ToolbarAndroid => onIconClicked
body: <p>I'm new to React native (and React) and I'm playing around a little bit with it.</p>
  
  <p>I managed to add a DrawerLayout that I can drag from the left of my screen.
  However I'd like to open it when I click on my menu icon in my ToolbarAndroid.</p>
  
  <p>I tried to use "refs" but it doesn't seem to work</p>
  
  <p>I hope I'm clear enough.</p>
  
  <p>Thank you</p>