Revert "[Java][Spring] Fix for #8659 - Different in-parameter types - fix for #9462

[agilob]

This reverts commit b9a1c8f.

Reverts of PR #9331 to fix #9462

However, the newly generated interface contract cannot be satisfied in a clean way, as MultipartFile is not supposed to be a return value. See Spring documentation of MultipartFile

A representation of an uploaded file received in a multipart request.

The file contents are either stored in memory or temporarily on disk. In either case, the user is responsible for copying file contents to a session-level or persistent store as and if desired. The temporary storage will be cleared at the end of request processing.

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@beckerjohannes @wing328 @EmhyrVarEmreis

[wing328]

@agilob thanks for the PR to revert the change.