Don't show attendee status for Exchange events

* There are serious issues with showing consistent and accurate attendee
  status for Exchange 2007 events
* Unless and until these can be resolved, it is better to simply not show
  the user the supposed attendee status (since it might well be wrong)
* In this CL, I never set the attendee status; therefore, it will appear
  "unknown" and be shown simply as "Guest" when viewing the Event in the
  Calendar app.
* Will create tracking bug for this, so that we can revisit for a later

Bug: 2524410
Change-Id: I97fdd26750c68ff25bbb102547071c728e4124a9
1 file changed