How do I set multiple hosts on druid.zk.service.host while running on kubernetes/K8s?

A community member was running a cluster on K8s and wondered how to set multiple hosts on druid.zk.service.host. The answer turned out to be a comma separated list, but the community member had to include {} as follows:

druid.zk.service.host={zk-persistent-0.zk-persistent.druid.svc.cluster.local,zk-persistent-1.zk-persistent.druid.svc.cluster.local,zk-persistent-2.zk-persistent.druid.svc.cluster.local}

Read about druid.zk.service.host here, and some troubleshooting and context here.