Upgrade graphql-java library to 20.4

[CNAChino]

This is just to upgrade graphql-java to 20.4.

• Adjust breaking code changes if any
• The test should be passing.

[rishu1601]

Is this open for work?

[ashpak-shaikh]

go for it and don't forget to star the repo

[tasneemkoushar]

@ashpak-shaikh is this issue still open, can I work on it?

[rishu1601]

I will raise a PR for this soon