[cern] Update kubernetes dashboard to v1.6.3

Cherry-picked from: https://review.openstack.org/#/c/507465/3 Ticket: OS-5184 It reverts [1] and enables the kubernetes dashboard again.

[1] https://gitlab.cern.ch/cloud-infrastructure/magnum/commit/e8a74c5a30a14cbc56791e320b19d9c4230b7196

v1.6.3 is the latest no-RBAC release of the dashboad. When we update out config to use RBAC we can move to v1.7.x.

This patch also drops the prometheus stack to make space in user_data. The prometheus stack will be added back as a software deployment.

Related-Bug: #1680900 Change-Id: I68a17d22dda9661c81f40bcc9db06f7456790958

Conflicts: magnum/drivers/common/templates/kubernetes/fragments/enable-node-exporter.sh magnum/drivers/common/templates/kubernetes/fragments/kube-dashboard-service.sh Note the INSECURE_REGISTRY_URL change, it expects the url to not end with / magnum/drivers/heat/k8s_template_def.py It leaves the enable_monitoring and grafana_password in the python code and ignores them in heat templates in order to modify only the templates. magnum/drivers/k8s_fedora_atomic_v1/templates/kubecluster.yaml it accepts the prometheus parameters but it does not pass them to the master or minion magnum/drivers/k8s_fedora_atomic_v1/templates/kubemaster.yaml magnum/tests/unit/conductor/handlers/test_k8s_cluster_conductor.py magnum/tests/unit/drivers/test_template_definition.py