title: Horizontal position of UISearchBar when using UISearchController and large titles
body: <p>UISearchController created and used like this in <code>viewDidLoad</code></p>
  
  <pre><code>search = UISearchController(searchResultsController: nil)
  search.searchResultsUpdater = self
  search.obscuresBackgroundDuringPresentation = false
  search.definesPresentationContext = true
  search.searchBar.placeholder = "Search books"
  
  navigationItem.searchController = search
  </code></pre>
  
  <p><strong>I need to change horizontal position</strong> (offset, inset?) of the searchBar (search text field?) to align with title and content. </p>
  
  <p><a href="https://i.stack.imgur.com/2PG9d.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/2PG9dm.jpg" alt="issue"></a></p>
  
  <p>I already tried to change the frame of searchBar in viewDidAppear (left pic below), but it goes back when text field becomes first responder (right pic).</p>
  
  <p><a href="https://i.stack.imgur.com/iedyBt.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/iedyBt.png" alt="frame changed in viewDidLoad"></a>
  <a href="https://i.stack.imgur.com/anXCrt.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/anXCrt.png" alt="frame is back when text field is first responder"></a></p>
  
  <p>Is there any working solution?</p>