Looker tightens custom TopoJSON URL validation and self-service modeling access

Custom TopoJSON URL validation is updated to improve security. This change is isolated to Google Maps rendering in preview. Existing dashboards and Looks with the Google Maps Enhancements preview feature enabled that use custom TopoJSON files may be impacted.

When you set up a connection, self-service modeling will now be available only if a role that grants create_self_service_from_table also selects it through that role's model set.