CLDCONNECT-1372 : Resolved Class Versioning & Operations hung issue

1. Upgraded the google-api-services-calendar version from
v3-rev9-1.7.2-beta to v3-rev77-1.17.0-rc
2. Removed unnecessary ‘@Optional’ annotations in the Google Calendar
Connector Class
3. Modified the model classes as a part of version upgrade.
4. Updated all the test cases & test data.
5. CLDCONNECT-1373  was as resolved due to upgrade of the google client
& calendar api.