Conflicting guidance on License Headers

[dbwiddis]

The CONTRIBUTING.md file in this repository specifies a longer license header.

This conflicts with apparent (authoritative?) guidance posted in a comment on the alerting project repo here, although the qualification of "like this one" isn't clear:
opensearch-project/alerting#136 (comment)

There was an apparently more authoritative version in issue #21 and PR #29 where the CONTRIBUTING file was updated with a shorter version.
@dblock asked:

is the short version the preferred version, @hyandell?

@hyandell replied:

Yes, that's the preferred version.

But then @dblock updated the header in #76 to include the more expansive language presently in the header based on this issue: opensearch-project/opensearch-java#178

That update stated that the change was "confirmed" but did not cite a reference.

But we still have some PRs updating per the older guidance such as opensearch-project/OpenSearch#4657

My ask:

1. Please confirm that the header in this repo's CONTRIBUTING file is the latest official guidance
2. Suggest someone with the admin-powers to do so edit the conflicting guidance in the linked issues above to add an "update" which points to the latest guidance