The invariantUUID metadata in the generated tosca template for a service/VF has changed to invariantUuid, causing failure in SO to parse the service csar.

This issue was introduced when ToscaMetadata class was replaced by a Map<String, String> in ToscaExportHandler in commit https://gerrit.onap.org/r/c/sdc/+/116625 . A difference in representation of invariantUUID in JsonPresentationFields compared with the ToscaMetadata class being the source of the problem