Fix worker_node_labels for initial Fedora CoreOS

* Add Terraform strip markers to consume beginning and
trailing whitespace in templated Kubelet arguments for
podman (Fedora CoreOS only)
* Fix initial `worker_node_labels` being quietly ignored
on Fedora CoreOS cloud platforms that offer the feature
* Close https://github.com/poseidon/typhoon/issues/650

google-cloud/fedora-coreos/kubernetes/workers/fcc/worker.yaml

@@ -66,9 +66,9 @@ systemd:
           --lock-file=/var/run/lock/kubelet.lock \
           --network-plugin=cni \
           --node-labels=node.kubernetes.io/node \
-          %{ for label in split(",", node_labels) }
+          %{~ for label in split(",", node_labels) ~}
           --node-labels=${label} \
-          %{ endfor ~}
+          %{~ endfor ~}
           --pod-manifest-path=/etc/kubernetes/manifests \
           --read-only-port=0 \
           --volume-plugin-dir=/var/lib/kubelet/volumeplugins