Show "no response" for all new calendar events in EAS < 14

* Continue to infer a response from busy status for updated events
* Note that there is NO way to be certain of an attendee's response
  in earlier versions of EAS
* Also, fix an obsolete comment in CalendarUtilities

Bug:  5314268
Change-Id: Ibb23bd68851d991c7a389f81ce9de341a8b8d6cb
2 files changed