Same here. Started approximately from yesterday.
Could disable just those notifications, but similar to the Google AR Services, disabling that nag also disables other, more important messages.
AFAIK, Google doesn't provide the granularity we need. Could be a feature request as part of the sandboxing. BTW, the sandboxing originally came from ProtonAsop, so if you don't get attention to feature requests here at GrapheneOS, you could make the request with the ProtonAsop project.