Replace 'whitelist' terminology in Java API

[tlfeng]

Description

Replace 'whitelist' terminology in Java API and Gradle project name.
Replacement rule: whitelist -> allowlist
This is a breaking change that will impact other programs using OpenSearch Java library.

Issues Resolved

Resolve #1683

Check List

• New functionality includes testing.
  • All tests pass
• New functionality has been documented.
  • New functionality has javadoc added
• Commits are signed per the DCO using --signoff

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.
For more information on following Developer Certificate of Origin and signing off your commits, please check here.

[opensearch-ci-bot]

❌   Gradle Check failure 581865bc4703120bf9cdae98a7722ff616b5c4e0
Log 5391

Reports 5391

[opensearch-ci-bot]

✅   Gradle Check success 77f7d72
Log 5395

Reports 5395

[saratvemulapalli]

@tlfeng is the change intended to go in 3.0.0 and not 2.0?

[tlfeng]

@nknize Thanks a lot for your review!
@saratvemulapalli Yes, it's target for version 3.0, I wanted to give the other developers more time to adapt the terminology change. These changes are public Java API which are packaged in jar file and published to Maven, ideally I should add @deprecate annotation first, but they are too many methods or classes to be deprecated, so I decided to rename them directly in next major version.

[saratvemulapalli]

Added this PR to the list: #3351