Shorten date/time info in event info to display in one line.

1) Don't show the year if it is the current year, 2) shorten day/month names for multiday events, 3) display "Today" or "Tomorrow" when possible, 4) use short timezone string. (b/6285801)

Change-Id: Idc4646c15f90ea6803cdff7cde985550501f62cf