Incorrect filebeat nginx mappings with kubernetes deployment

While using the k8s manifest from here https://raw.githubusercontent.com/elastic/beats/7.5/deploy/kubernetes/filebeat-kubernetes.yaml

The nginx module mappings looks like these:

        "nginx" : {
      "properties" : {
        "access" : {
          "properties" : {
            "geoip" : {
              "type" : "object"
            },
            "user_agent" : {
              "type" : "object"
            }
          }
        },
        "error" : {
          "properties" : {
            "connection_id" : {
              "type" : "long"
            }
          }
        }
      }
    },

I was expecting to get the mappings as defined in the fields.yaml file.

Most of the nginx properties are defined as aliases. It feels like the aliases are not getting their way into the final template.