I am developing a Splunk SOAR app that retrieve a json from our backend and ingest it into a container in splunk soar. However, I need to show some fields that are not included in the container schema and i want those custom fields to be deployed with my app. Therefore my question, Is it possible to add custom fields to a splunk phantom container schema programmatically so our customers do not need to create them manually in the Splunk SOAR user interface?