fix: switch svpc access to explicit dep on service enablement

[bharathkkb]

Context: b/362272932

[bharathkkb]

Validated in test logs that google_project_iam_member in svpc access still awaits API enablement

After

module.example.module.service-project-b.module.project-factory.module.project_services.google_project_service.project_services["dataproc.googleapis.com"]: Still creating... [20s elapsed]
module.example.module.service-project-b.module.project-factory.module.project_services.google_project_service.project_services["dataproc.googleapis.com"]: Creation complete after 22s [id=.../dataproc.googleapis.com]
       ...
module.example.module.service-project-b.module.shared_vpc_access.google_project_iam_member.service_shared_vpc_user["dataproc.googleapis.com"]: Creating...
       ```