[BUG][Java] duplicate @JsonTypeName annotation

Created by: cachescrubber

Bug Report Checklist

• Have you tested with the latest master to confirm the issue still exists?
• [x ] Have you searched for related issues/PRs?

Description

If a Spec uses inheritance, and a Schema is considered to be sanitised (isClassnameSanitized is true) the java generator will generate a duplicate @JsonTypeName("Model_Name")annotation.

See Java/pojo.mustache and Java/typeInfoAnnotation.mustache.

openapi-generator version

5.4.0

Suggest a fix

I'm happy to provide PR with a fix, but would like to discuss prior with the core team and / or Java technical committee wether to unconditionally include @JsonTypeName or use the isClassnameSanitized condition.

{{#isClassnameSanitized}}
@JsonTypeName("{{name}}")
{{/isClassnameSanitized}}