title: safeAreaInsets for UIToolbar without using Constraints
body: <p>I have an app that does all UI programmatically without using auto layout or any sort of constraints.  At the bottom of the screen is a UIToolbar.  I am trying to lay this out to play well with the iPhone X screen's bottom safe area but due to the design of the VCs I cannot use layout constraints.  </p>
  
  <p>So in my layoutSubviews callback I am doing this:</p>
  
  <pre><code>if (@available(iOS 11.0, *)) {
      toolbarHeight += UIApplication.sharedApplication.keyWindow.safeAreaInsets.bottom;
  }
  </code></pre>
  
  <p>Then later setting the UIToolbar's frame directly with toolBarHeight.  </p>
  
  <p>This works in that the toolbar is now the correct height and adjusts when you rotate to landscape, but the problem is that the Toolbar's buttons are not top aligned, but rather centered vertically.  I can't figure out how to set the contentInsets or some way to top align the UIToolbar buttons without using constraints.  </p>
  
  <p>Any ideas?</p>