title: onPrepareOptionsMenu only called once on Android 2.3
body: <p>I am putting some code to dynamically control the visibility of some menu items in Activity.onPrepareOptionsMenu. It works perfect on android 5.0. However, when I tried it on android 2.3, I found onPrepareOptionsMenu is called only once during the life time of the entire app. And the trouble with that invalidateOptionsMenu is not available on android 2.3 either. </p>
  
  <p>Any idea how to solve this problem?</p>