title: iOS7 delay in applying UIKeyboardAppearanceDark
body: <p>I am seeing a strange behavior in iOS7 where I set the keyboard appearance to UIKeyboardAppearanceDark in viewDidLoad, but the keyboard will initially appear in the default (light gray) style, and then a second later switch to the dark style. </p>
  
  <p>I further see this behavior in a different UIViewController when I set the keyboard appearance in a XIB file - the view loads and quickly flashes from light to dark as the view appears.</p>
  
  <p>Can anyone suggest a reason for this behavior, or is this a bug in iOS7? </p>