title: How to hide top bar on QLPreviewController by default
body: <p>I am presenting a QuickLook preview controller like so:</p>
  
  <pre><code> QLPreviewController *qlController = [[QLPreviewController alloc] init];
      qlController.dataSource = self;
      qlController.delegate = self;
      dispatch_async(dispatch_get_main_queue(), ^{
          [rootVC presentViewController:qlController animated:NO completion:nil];
      });
  </code></pre>
  
  <p>I'm passing it a usdz preview item. As soon as the item loads in the top bar it disappears but the effect is jarring.</p>
  
  <p>Is there any way to hide this top bar (highlighted in yellow) by default so it never shows up?</p>
  
  <p><a href="https://i.stack.imgur.com/qsPoil.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/qsPoil.jpg" alt="enter image description here"></a></p>