message: Add key, headers and timestamp type fields
diff: @@ -389,6 +389,18 @@ components:
  timestamp:
  type: string
  format: date-time
  + timestampType:
  + type: string
  + enum:
  + - NO_TIMESTAMP_TYPE
  + - CREATE_TIME
  + - LOG_APPEND_TIME
  + key:
  + type: string
  + headers:
  + type: object
  + additionalProperties:
  + type: string
  content:
  type: string
  required:
  