Fix flaky test cases

[RS146BIJAY]

Description

Fixing following test cases:

1. InternalEngineTests.testUnreferencedFileCleanUpOnSegmentMergeFailureWithCleanUpEnabled: Right now merge policy created for IndexWriter can create an Alcoholic Merge policy as well. This does not sometimes trigger segment merges. Also using ForceMerge policy to avoid regular merge (triggered due to) closing shard before force merge kicks in.
2. org.opensearch.index.engine.InternalEngineTests.testUnreferencedFileCleanUpOnSegmentMergeFailureWithCleanUpDisabled
3. InternalEngineTests.testUnreferencedFileCleanUpFailsOnSegmentMergeFailureWhenDirectoryClosed: Right now merge policy created for IndexWriter can create an Alcoholic Merge policy as well. This does not sometimes trigger segment merges.
4. DiskThresholdDeciderIT.testIndexCreateBlockIsRemovedWhenAnyNodesNotExceedHighWatermarkWithAutoReleaseEnabled: Need to refresh DiskThresholdMonitor periodically as well to remove the node from high watermark breached list once available space is above high watermark on all nodes.
5. ClusterShardLimitIT.testCreateIndexWithMaxClusterShardSetting: Ensure Max shard per cluster is always greater than max shard per node.

Related Issues

#10903
#10739
#9891
#6445
#6287

Check List

• New functionality includes testing.
  • All tests pass
• New functionality has been documented.
  • New functionality has javadoc added
• Failing checks are inspected and point to the corresponding known issue(s) (See: Troubleshooting Failing Builds)
• Commits are signed per the DCO using --signoff
• Commit changes are listed out in CHANGELOG.md file (See: Changelog)
• Public documentation issue/PR created

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[github-actions]

❌ Gradle check result for 0da1a97: 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]

Compatibility status:

Checks if related components are compatible with change cfc429a

Incompatible components

Skipped components

Compatible components

Compatible components: [https://github.com/opensearch-project/custom-codecs.git, https://github.com/opensearch-project/asynchronous-search.git, https://github.com/opensearch-project/performance-analyzer-rca.git, https://github.com/opensearch-project/flow-framework.git, https://github.com/opensearch-project/cross-cluster-replication.git, https://github.com/opensearch-project/job-scheduler.git, https://github.com/opensearch-project/reporting.git, https://github.com/opensearch-project/security.git, https://github.com/opensearch-project/geospatial.git, https://github.com/opensearch-project/opensearch-oci-object-storage.git, https://github.com/opensearch-project/k-nn.git, https://github.com/opensearch-project/neural-search.git, https://github.com/opensearch-project/common-utils.git, https://github.com/opensearch-project/security-analytics.git, https://github.com/opensearch-project/anomaly-detection.git, https://github.com/opensearch-project/performance-analyzer.git, https://github.com/opensearch-project/notifications.git, https://github.com/opensearch-project/ml-commons.git, https://github.com/opensearch-project/index-management.git, https://github.com/opensearch-project/observability.git, https://github.com/opensearch-project/alerting.git, https://github.com/opensearch-project/sql.git]

[github-actions]

✅ Gradle check result for 045e7c0: SUCCESS

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Comparison is base (8489294) 71.32% compared to head (cfc429a) 71.35%.
Report is 9 commits behind head on main.

Additional details and impacted files

@@             Coverage Diff              @@
##               main   #12320      +/-   ##
============================================
+ Coverage     71.32%   71.35%   +0.03%     
- Complexity    59764    59777      +13     
============================================
  Files          4959     4959              
  Lines        281129   281129              
  Branches      40857    40857              
============================================
+ Hits         200513   200608      +95     
+ Misses        63947    63840     -107     
- Partials      16669    16681      +12     

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[github-actions]

❌ Gradle check result for 506ae7e: 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 c62d913: UNSTABLE

• TEST FAILURES:

      1 org.opensearch.remotestore.RemoteIndexPrimaryRelocationIT.testPrimaryRelocationWhileIndexing
      1 org.opensearch.http.SearchRestCancellationIT.testAutomaticCancellationMultiSearchDuringFetchPhase

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

[github-actions]

❌ Gradle check result for d9f1307: 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 cfc429a: 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 cfc429a: 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?

[RS146BIJAY]

Ran each of the above tests 1000 times without any failures on local

[github-actions]

❕ Gradle check result for cfc429a: UNSTABLE

• TEST FAILURES:

      1 org.opensearch.remotestore.RemoteIndexPrimaryRelocationIT.testPrimaryRelocationWhileIndexing

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