Automatic merge from submit-queue
Added configurable etcd initial-cluster-state to kube-up script.
Added configurable etcd initial-cluster-state to kube-up script. This
allows creation of multi-master cluster from scratch. This is a
cherry-pick of #41320 from 1.5 branch.
```release-note
Added configurable etcd initial-cluster-state to kube-up script.
```