Set up a pipeline or maven plugin to enforce java format

As discussed in https://github.com/apache/incubator-pinot/pull/6721

>There are lots of files are not formatted properly, engineers often forget to format it before commit. We need either setup a Github workflow/pipeline, or a maven plugin to enforce java format

Some tools may be useful:

CLI tools:
* https://github.com/google/google-java-format

Maven plugins:
* https://github.com/diffplug/spotless/tree/main/plugin-maven
* https://github.com/coveooss/fmt-maven-plugin
* https://github.com/talios/googleformatter-maven-plugin
* https://github.com/Cosium/git-code-format-maven-plugin

Start by inspecting Pinot's Maven build configuration and GitHub workflow setup, then compare the listed google-java-format and Maven plugin options. Choose one enforcement path, configure it for the Java sources, and verify that the existing repository passes the formatting check.

Written by the indexing model from the issue text.