[Star tree] Rename count to value_count to be inline with aggregations

[bharath-techie]

Description

Rename "count" to "value_count" to be inline with naming conventions of search aggregations

Related Issues

Solves part of #15148

Check List

• Functionality includes testing.
• API changes companion pull request created, if applicable.
• Public documentation issue/PR created, if applicable.

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.

[github-actions]

❌ Gradle check result for 1a85868: FAILURE

Please examine the workflow log, locate, and copy-paste the failure(s) below, then iterate to green. Is the failure a flaky test unrelated to your change?

[github-actions]

❌ Gradle check result for a842fa8: FAILURE

Please examine the workflow log, locate, and copy-paste the failure(s) below, then iterate to green. Is the failure a flaky test unrelated to your change?

[github-actions]

❕ Gradle check result for 8ac65ac: UNSTABLE

Please review all flaky tests that succeeded after retry and create an issue if one does not already exist to track the flaky failure.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 71.88%. Comparing base (9661e8d) to head (e878a36).
Report is 27 commits behind head on main.

Additional details and impacted files

@@             Coverage Diff              @@
##               main   #15147      +/-   ##
============================================
+ Coverage     71.81%   71.88%   +0.06%     
- Complexity    63053    63119      +66     
============================================
  Files          5212     5212              
  Lines        295649   295649              
  Branches      42692    42692              
============================================
+ Hits         212331   212514     +183     
+ Misses        65862    65676     -186     
- Partials      17456    17459       +3     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[sarthakaggarwal97]

LGTM! thanks @bharath-techie

Adding here for reference: https://opensearch.org/docs/latest/aggregations/metric/value-count/

[ajaymovva]

LGTM

[dblock]

Just confirming that this is not a breaking change for something that we GA-ed already?

[sarthakaggarwal97]

Just confirming that this is not a breaking change for something that we GA-ed already?

@dblock Star Tree is yet to be GA-ed as a feature. It still under development, and the plan is to backport it to 2.x for OS 2.17. We introduced a count as a aggregation here, but its still a part of main branch only.
This PR brings star tree count aggregation inline with present aggregations.

[dblock]

@bharath-techie You might want to start drafting API changes in https://github.com/opensearch-project/opensearch-api-specification earlier than later for this feature. That repo supports testing with feature flags enabled, too.

[bharath-techie]

@bharath-techie You might want to start drafting API changes in https://github.com/opensearch-project/opensearch-api-specification earlier than later for this feature. That repo supports testing with feature flags enabled, too.

Sure thanks @dblock let me track this - will create an associated issue as well.

[github-actions]

❕ Gradle check result for e878a36: UNSTABLE

Please review all flaky tests that succeeded after retry and create an issue if one does not already exist to track the flaky failure.