title: Setting accessibility hint to UINavigationItem
body: <p>I would like the voiceover to read out a custom message after the title for the view is read out. To achieve this, I have set the accessibility hint for the navigation item.</p>
  
  <pre><code>self.navigationItem.accessibilityHint= @"Custom message.";
  </code></pre>
  
  <p>However the voiceover does not read out the hint for a UINavigationItem. It only reads out the title and stops at that. 
  Appending text to accessibility label is an option, I believe is a workaround if this doesn't work. Any other suggestions?</p>
  
  <p>What I'm trying to achieve is to instruct the user to handover the device to another user when a particular screen is shown. I want the instruction to be read out after the title is read out. </p>