[cern] Add service account to daemonset in traefik
Cherry-pick: https://review.openstack.org/#/c/553789/
This allows traefik to access the resources protected by Kubernetes RBAC
Change-Id: Ia374215dd67afce6125fbfd6e322e5e9d15b4b0b Closes-Bug: #1755844 (cherry picked from commit 79f4cc0c)