[Backport-2.x] Add Segment download stats to remotestore stats API

[shourya035]

Description

Backport #8718 to 2.x branch

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)

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-trigger-bot]

Compatibility status:

> Task :checkCompatibility
Checking compatibility for: https://github.com/opensearch-project/opensearch-oci-object-storage.git with ref: 2.x
Skipping compatibility check for https://github.com/opensearch-project/opensearch-oci-object-storage.git
Incompatible components: [https://github.com/opensearch-project/security.git, https://github.com/opensearch-project/alerting.git, https://github.com/opensearch-project/index-management.git, https://github.com/opensearch-project/anomaly-detection.git, https://github.com/opensearch-project/sql.git, https://github.com/opensearch-project/k-nn.git, https://github.com/opensearch-project/cross-cluster-replication.git, https://github.com/opensearch-project/geospatial.git, https://github.com/opensearch-project/ml-commons.git, https://github.com/opensearch-project/notifications.git]
Components skipped due to git failures: [https://github.com/opensearch-project/opensearch-oci-object-storage.git]
Compatible components: [https://github.com/opensearch-project/asynchronous-search.git, https://github.com/opensearch-project/job-scheduler.git, https://github.com/opensearch-project/observability.git, https://github.com/opensearch-project/common-utils.git, https://github.com/opensearch-project/reporting.git, https://github.com/opensearch-project/performance-analyzer.git, https://github.com/opensearch-project/neural-search.git, https://github.com/opensearch-project/performance-analyzer-rca.git, https://github.com/opensearch-project/security-analytics.git]

BUILD SUCCESSFUL in 25m 59s

[github-actions]

Gradle Check (Jenkins) Run Completed with:

• RESULT: UNSTABLE ❕
• TEST FAILURES:

      1 org.opensearch.search.SearchWeightedRoutingIT.testStrictWeightedRoutingWithCustomString

• URL: https://build.ci.opensearch.org/job/gradle-check/21791/
• CommitID: 81cc085
  Please review all flaky tests that succeeded after retry and create an issue if one does not already exist to track the flaky failure.