title: TimePicker in PreferenceScreen
body: <p>I'd like to create a preference field called <code>Interval</code> and I want to be able to popup a <code>TimePicker</code> and set a <code>mm:ss</code> formated value with minimal value <code>00:30</code> and step 30 seconds.</p>
  
  <p>Is it possible to use <code>TimePicker</code> in <code>PreferenceScreen</code> ?</p>