ci: update polaris plugin version and add headlamp SA to RBAC

- Update headlamp-static-plugin-values.yaml to 0.7.2
- Add headlamp service account to polaris-dashboard-proxy-reader RoleBinding
- Update documentation references from headlamp-polaris-plugin to headlamp-polaris

Co-Authored-By: Paperclip <noreply@paperclip.ing>

deployment/polaris-rbac.yaml

@@ -22,6 +22,9 @@ subjects:
   - kind: Group
     name: system:authenticated
     apiGroup: rbac.authorization.k8s.io
+  - kind: ServiceAccount
+    name: headlamp
+    namespace: kube-system
 roleRef:
   kind: Role
   name: polaris-dashboard-proxy-reader