Prohibit a Map usage pattern replaceable with putIfAbsent()

[leventov]

This pattern is specifically described in this tutorial: https://github.com/apache/incubator-druid/blob/a4270da5f3de25f1182cfdf2ac0d9de7781312cf/ci/README_TeamCity.md#creating-a-custom-inspection-from-a-structural-search-pattern

A part of #4034.

[sashidhar]

@leventov, Raised #7764. Please review the pull request.