Update the document BUILDING.md: opensearch.opensearchplugin add groupID field to org.opensearch.plugin

[prudhvigodithi]

Description

Update the document BUILDING.md
The configuration modification for the gradle plugin opensearch.opensearchplugin to make sure the groupId is added as org.opensearch.plugin to the publication pluginZip inside the build.gradle file.

Related META issue

Part of: opensearch-project/opensearch-build#2521
From solution: opensearch-project/OpenSearch#3692

Current Behavior

The opensearch.opensearchplugin uses the default setting for groupId as org.opensearch.plugin, this when extended with open source community, it should be feasible to ammend the groupId as per required, hence for opensearch plugins the groupId should be mentioned as org.opensearch.plugin to make sure the opensearch plugins are published to this groupID and for other generic uses this can be extended to the custom groupId.

Expected Behavior

Once the groupId is added as org.opensearch.plugin to the publication pluginZip inside the build.gradle file, the plugin zips should continue to be published to the existing groupID.

Proposed solution

Solution from the PR: opensearch-project/OpenSearch#3692

[prudhvigodithi]

Hey @lukas-vlcek when you get a chance can you please update the document with the latest changes from your PR?
Thank you
@dblock @bbarani @reta

[lukas-vlcek]

@prudhvigodithi Please see #175

[prudhvigodithi]

Thanks @lukas-vlcek closing this issue and related PR is merged #175.