title: Make UITextField with VoiceOver read numbers as digits
body: <p>Our App has a few <code>UITextField</code> where users enter alphanumeric input codes such as "AA149873A". </p>
  
  <p>We'd like voice over to read these as "A A 1 4 9 8 7 2 A", but it instead reads the digits as a number: "One hundred and forty nine thousand, eight hundred and seventy three". </p>
  
  <p>Is there some way to configure <code>UITextField</code> so that it knows its content shouldn't be thought of as numbers, but individual digits?</p>
  
  <p>Thanks.</p>