title: React Native Navigation v2 (wix) Disable TopBar
body: <p>I am using the React-Native-Navigation v2 from wix (NOT React-Navigation).
  I tried disabling the topBar which is rendered by default.</p>
  
  <p>I used following options and am rendering bottomTabs: </p>
  
  <pre><code>Navigation.setDefaultOptions({
    topBar: {
      visible: false,
      _height: 0,
      drawBehind: true,
    },
  });
  </code></pre>
  
  <p>The topBar disapears but shows an drawBehind animation on initial opening of the Tabs of bottomTabs.</p>
  
  <p>Is there a way to disable the topBar ?</p>
  
  <p>Best regards</p>