title: UINavigationController title view truncates briefly when moving from view with smaller font to larger font
body: <p>My root view on a <code>UINavigationController</code> has a title with a font point size of 36.  I perform a push segue to a view where the navigation bar title has a font size of 24 (the title is a longer string).  I'm setting the font size for each view with <code>setTitleTextAttributes:</code> in <code>viewWillAppear:</code> and the change in font size is made (from larger font to smaller font.</p>
  
  <p>The problem is that when I go back to the root view, the title will briefly be truncated before increasing the size to 36.</p>
  
  <p><img src="https://i.stack.imgur.com/3wEDa.gif" alt="Nav Bar"></p>
  
  <p>I'm setting the title strings in a Storyboard.  All I really need to change is the font size between some views.  Is there a way to correct this without creating a new title label for each view?</p>