Are you referring to something built into VS Code, or an extension? It looks you're talking about https://github.com/redhat-developer/vscode-java, which is RedHat's doing.

Yes, my DEV VM tended to fill up with VSCode backups as well. I finally expanded the disk so it's less of an issue today, but for a while ENOSPC was resolved by cleaning up ~/.vscode-server/cli/servers.