[FEATURE] Support Java jar publishing to remote Maven repository

[karenyrx]

Is your feature request related to a problem?

The repository currently generates a maven jar opensearch-protobuf-1.0.0.jar under generated/maven/. This jar should be uploaded to the Maven central repository and also the snapshot repository.

The jar will then be used in a build.gradle file like:

dependencies {
  implementation "org.opensearch.protobuf:opensearch-protobuf:1.0.0"
}

opensearch-project/.github#305 is the ticket to configure permissions to upload to Maven. GHA/Build files within this repository will also be needed.

What solution would you like?

Publish the existing bazel-generated artifacts to maven. Perhaps follow something like https://medium.com/wix-engineering/how-to-publish-artifacts-from-bazel-to-maven-central-71da0cf990f5

What alternatives have you considered?

Gradle instead of Bazel for publishing. This has not been fully ruled out yet, but for consistency with other languages in this repository, Bazel is slightly more preferred

Do you have any additional context?

This is needed by April 8th (latest) to meet the OS 3.0 beta release code completion deadline. It will be used by all GRPC PRs in core.