[Bug] Unlisted surveys don't show up for eMail-invitees

[jo-spek]

Relates to ground-platform issue https://github.com/google/ground-platform/issues/2285

When adding data collectors, survey organizers etc. on an access "Restricted" survey, the survey immediately appears in the survey list in the application.

However, if the survey is changed to "Unlisted", it disappears from the list (if not prior downloaded) and has to be added by link/QR code.