Fix conversion of UNTIL date in RRULEs to EAS calendar dates

* Because we were sending these in the wrong format, upsynced changes
  were failing, with the result that both the original event and
  the "new" event (from the UNTIL date forward) remained in the calendar
* Fix is to send the proper format; unit test updated to reflect the
  change
* Also, we only send the date of an UNTIL, rather than the to-the-minute
  time; it turns out that EAS expects to see only a day for UNTIL.

Bug: 2561818
Change-Id: Ic4eacbe96c713d58c637386ceab2cf22ebe3c2d4
2 files changed