Cherry-pick: https://review.openstack.org/#/c/436037
By default, API service with service account is accessible from inside the cluster at the address 10.254.0.1. This IP should be added to SANS when generating the certs.
Fixes-bug: #1660811 Change-Id: I214b4296bea55bb0c4015165c56fbd8ca3cebd39
Conflicts: magnum/drivers/k8s_coreos_v1/templates/fragments/make-cert.yaml
Closes #4120