BlenderBot2 interactive_web: Object of type AverageMetric is not JSON serializable   (#3821)
BlenderBot2 interactive_web: Object of type AverageMetric is not JSON serializable   (#3821)

* cast the returned metrics to int to avoid errors when json serializing AverageMetric objects

* removing debug logging stmt

* use model_response.json_safe_payload method
facebookresearch/ParlAI,facebookresearch/ParlAI,facebookresearch/ParlAI,facebookresearch/ParlAI,facebookresearch/ParlAI