title: Present UISearchController from button animates keyboard appearance strangely on first presentation
body: <p>I am presenting a <code>UISearchController</code> from a search icon on my navigation bar and when the controller is presented the first time the keyboard appears to zoom in from the left side instead of appearing from the bottom. But when presented a second time (and anytime thereafter), it appears correctly with the normal animation. </p>
  
  <p>Any idea why this would happen? Is there a different way I should be presenting the search controller?</p>
  
  <p>I have tried presenting it directly on self (which is a <code>UITableViewController</code>) instead of the <code>UINavigationController</code> parent with no difference.</p>
  
  <p>Should I just learn to love this and forget about it? :)</p>
  
  <p>Relevant presentation code:</p>
  
  <pre><code>// viewDidLoad
  UISearchController *searchController = [[UISearchController alloc] initWithSearchResultsController:nil];
          [searchController setDimsBackgroundDuringPresentation:NO];
          [searchController setHidesNavigationBarDuringPresentation:NO];
          [searchController setDelegate:self];
          [searchController setSearchResultsUpdater:self];
          self.searchController = searchController;
  
  # pragma mark - Actions
  
  - (void)search:(id)sender {
      [self.searchController setActive:YES];
  }
  
  # pragma mark - UISearchControllerDelegate
  
  - (void)presentSearchController:(UISearchController *)searchController {
      [self.navigationController presentViewController:self.searchController animated:YES completion:nil];
  }
  </code></pre>