Did you check the docs?
Is your feature request related to a problem? Please describe.
Project metadata should not be generated inside a project.
redhat-developer/vscode-java#618
https://devblogs.microsoft.com/java/say-goodbye-to-project-files-in-1-1-0/
Describe the solution you'd like
jdtls has an option which can be passed by using -Djava.import.generatesMetadataFilesAtProjectRoot=false. This is the default i.e. vscode uses thought they provide an option so that user can change it.
Describe alternatives you've considered
Think there's none unless you somehow try to override whole command launching jdtls.
Additional context
No response