[JAVA] fix artifactVersion is not taken from specification

Created by: karismann

when not provided by generator option

PR checklist

• Read the contribution guidelines.
• Ran the shell script under ./bin/ to update Petstore sample so that CIs can verify the change. (For instance, only need to run ./bin/{LANG}-petstore.sh, ./bin/openapi3/{LANG}-petstore.sh if updating the {LANG} (e.g. php, ruby, python, etc) code generator or {LANG} client's mustache templates). Windows batch files can be found in .\bin\windows\.
• Filed the PR against the correct branch: master, 3.4.x, 4.0.x. Default: master.
• Copied the technical committee to review the pull request if your PR is targeting a particular programming language.

@bbdouglas (2017/07) @sreeshas (2017/08) @jfiala (2017/08) @lukoyanov (2017/09) @cbornet (2017/09) @jeff9finger (2018/01) @Zomzog (2019/04)

Description of the PR

fix #1815 (closed) fix #2033 PR feature :

• If no artifactVersion is provided in additional properties, version from API specification is used. If none of them is provided then fallbacks to default version (1.0.0)