[Backport 2.x] Change filenames for IndexMetadata and Manifest [#10557]

[dhwanilpatel]

Description

This PR includes backporting of below PR:

• Change filenames for IndexMetadata and Manifest: [ Original PR: Change filenames for IndexMetadata and Manifest #10557 ]

Changes done during backporting:

• Resolved conflicts of change log.

Related Issues

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
• Commit changes are listed out in CHANGELOG.md file (See: Changelog)
• Public documentation issue/PR created

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]

Compatibility status:

Checks if related components are compatible with change 4944ab6

Incompatible components

Skipped components

Compatible components

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

[github-actions]

Gradle Check (Jenkins) Run Completed with:

• RESULT: FAILURE ❌
• URL: https://build.ci.opensearch.org/job/gradle-check/28263/
• CommitID: c74102f
  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 (Jenkins) Run Completed with:

• RESULT: FAILURE ❌
• URL: https://build.ci.opensearch.org/job/gradle-check/28266/
• CommitID: 81133b8
  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 (Jenkins) Run Completed with:

• RESULT: UNSTABLE ❕
• TEST FAILURES:

      1 org.opensearch.snapshots.DedicatedClusterSnapshotRestoreIT.testIndexDeletionDuringSnapshotCreationInQueue

• URL: https://build.ci.opensearch.org/job/gradle-check/28283/
• CommitID: 4944ab6
  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

Merging #10700 (4944ab6) into 2.x (e611185) will decrease coverage by 0.01%.
Report is 7 commits behind head on 2.x.
The diff coverage is 72.43%.

@@             Coverage Diff              @@
##                2.x   #10700      +/-   ##
============================================
- Coverage     70.93%   70.92%   -0.01%     
+ Complexity    58575    58556      -19     
============================================
  Files          4830     4830              
  Lines        276453   276580     +127     
  Branches      40588    40610      +22     
============================================
+ Hits         196091   196172      +81     
- Misses        63676    63709      +33     
- Partials      16686    16699      +13     

Files	Coverage Δ
...rg/opensearch/telemetry/tracing/DefaultTracer.java	100.00% <100.00%> (ø)
.../opensearch/telemetry/tracing/noop/NoopTracer.java	87.50% <100.00%> (+1.78%)	⬆️
...ch/repositories/gcs/GoogleCloudStorageService.java	82.43% <100.00%> (ø)
...search/telemetry/metrics/OTelMetricsTelemetry.java	100.00% <100.00%> (ø)
...rg/opensearch/telemetry/tracing/OTelTelemetry.java	100.00% <100.00%> (ø)
...search/telemetry/tracing/OTelTracingTelemetry.java	95.83% <100.00%> (+0.37%)	⬆️
...rg/opensearch/common/settings/ClusterSettings.java	92.85% <100.00%> (ø)
...va/org/opensearch/telemetry/TelemetrySettings.java	90.90% <100.00%> (+3.40%)	⬆️
...rg/opensearch/telemetry/tracing/WrappedTracer.java	78.57% <100.00%> (+1.64%)	⬆️
...lemetry/tracing/channels/TraceableHttpChannel.java	54.54% <100.00%> (ø)
... and 10 more

... and 446 files with indirect coverage changes