Downgrade version to 2.18.0 for ser/de of new ClusterStatsRequest met…

[SwethaGuptha]

…tric params.

Description

Downgrade version to 2.18.0 for ser/de of new ClusterStatsRequest metric params added n #15938

Related Issues

Resolves #[Issue number to be closed when this PR is merged]

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 c03c2c4: 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

Attention: Patch coverage is 50.00000% with 2 lines in your changes missing coverage. Please review.

Project coverage is 72.00%. Comparing base (6891267) to head (c03c2c4).
Report is 5 commits behind head on main.

Files with missing lines	Patch %	Lines
...ction/admin/cluster/stats/ClusterStatsRequest.java	50.00%	0 Missing and 2 partials ⚠️

Additional details and impacted files

@@             Coverage Diff              @@
##               main   #16441      +/-   ##
============================================
- Coverage     72.08%   72.00%   -0.09%     
+ Complexity    65035    64981      -54     
============================================
  Files          5313     5313              
  Lines        303294   303302       +8     
  Branches      43888    43888              
============================================
- Hits         218631   218391     -240     
- Misses        66757    66926     +169     
- Partials      17906    17985      +79     

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