[GRADLE] upgrade to 2.14.1 in java/scala/androit client to fix Vulnerability

[karismann]

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, ./bin/security/{LANG}-petstore.sh and ./bin/openapi3/security/{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)
  @clasnake (2017/07), @jimschubert (2017/09) , @shijinkui (2018/01), @ramzimaalej (2018/03)
  @jaz-ah (2017/09)

Description of the PR

fix #2094
remove unused folder samples/client/petstore/java/okhttp-gson/bin added recenty (by mistake i think)

[jimschubert]

Thanks! This looks fairly straightforward and someone can merge once the integration tests succeed.