[Feature][connector][kafka] Supplement the test case in json format

[MonsterChenzhuo]

Purpose of this pull request

close #3872

Check list

• [ ] Code changed are covered with tests, or it does not need tests for reason:
• [ ] If any new Jar binary package adding in your PR, please add License Notice according New License Guide
• [ ] If necessary, please update the documentation to describe the new feature. https://github.com/apache/incubator-seatunnel/tree/dev/docs
• [ ] If you are contributing the connector code, please check that the following files are updated:
  1. Update change log that in connector document. For more details you can refer to connector-v2
  2. Update plugin-mapping.properties and add new connector information in it
  3. Update the pom file of seatunnel-dist
• [ ] Update the release-note.

[MonsterChenzhuo]

cc @Hisoka-X @hailin0

[Hisoka-X]

The test case not passed, please fix it. Thanks.

[MonsterChenzhuo]

@Hisoka-X Thanks for your review,I have made the changes.