Calendar attendees and reminder fixes

Calendar attendees and reminder fixes

- b/2027729 Fixed the crash that happens when you change orientation while scrolling in agenda view
- b/2038978 Fixed the crash where all the attendees were previous removed by an error
- b/2033853 Fixed the problem where reminders weren't being saved.
- b/2027740 Improved logic on when to allow the user to supply a response to an event. It is still not perfect as we are wait for more
- b/2024425 Allow the user to delete the event even if they didn't create the event
- b/2030453 Hide delete button when creating new events
- Fixed the crash that happens when you click on revert while creating new events (only happens when you have an empty calendar)
- Improved performance by writing the attendees to the content provider iif they have changed.
- Fixed the title bar to correctly say "View Event" or "View Meeting Invitation" depending on the event.
- Fixed the problem where existing attendees weren't shown during edit event.
info from the server team.
- Added rect info in the intent SHOW_OR_CREATE_CONTACT. Can't test yet as my phone has contact sync problems.