[BUG][JAVA] Files resources conflicts with native java.io.File

Bug Report Checklist

• Have you provided a full/minimal spec to reproduce the issue?
• Have you validated the input using an OpenAPI validator (example)?
• What's the version of OpenAPI Generator used?
• Have you search for related issues/PRs?
• What's the actual output vs expected output?
• [Optional] Bounty to sponsor the fix (example)

Description

We have an endpoint for getting a file GET /api/files/{id} which returns a custom File object. The code generated with openapi-generator is returning a native java.io.File object.

openapi-generator version

4.3.0

OpenAPI declaration file content or url

https://catalyticsdkapi.azurewebsites.net/swagger/v1/swagger.json

Command line used for generation

Steps to reproduce

`$ openapi-generator generate -i https://catalyticsdkapi.azurewebsites.net/swagger/v1/swagger.json -g java -o new --additional-properties=apiPackage=org.catalytic.sdk.api,modelPackage=org.catalytic.sdk.model,dateLibrary=java8,groupId=org.catalytic,invokerPackage=org.catalytic.sdk,java8=true,hideGenerationTimestamp=true --skip-validate-spec

Related issues/PRs

Suggest a fix

Start with the generation command and the linked swagger.json, then inspect the generated Java client and model output to find where the custom File response becomes java.io.File. Reproduce with OpenAPI Generator 4.3.0; done when the generated client preserves the declared custom File type without the native java.io.File conflict.