Group events show all attendees email addresses in guests calendar event

[McPizza0]

Issue Summary

When joining a group event as a guest, I can see all other attendees email addresses in the calendar event. The calendar event is updated as guests are added or confirm.

Steps to Reproduce

Create Group Event Register as guest with other email Register as 2nd guest with yet another email

Observe calendar event

Any other relevant information. For example, why do you consider this a bug and what did you expect to happen instead?

Technical details

Observed in Google Mail/cal - May not be reproducible outside of G