CE-1774: fix serialize/deserialize preview generation request

Fixes one ... last ... thing ...

The convention should be some_variable_name, not someVariableName. Updated Swagger def looks good now:

"PreviewGenerationRequest": {
                "type": "object",
                "properties": {
                    "type_revision": {
                        "type": "string"
                    },
                    "config_revision": {
                        "type": "string"
                    },
                    "config_name": {
                        "type": "string"
                    }
                }
            }