On Google cloud it's always four nameservers like

    ns-cloud-c1.googledomains.com
    ns-cloud-c2.googledomains.com
    ns-cloud-c3.googledomains.com
    ns-cloud-c4.googledomains.com

Would not make any sense to do four of them if it's a single AZ. Also, they are geo-aware and routed to your nearest region.