[Remote Translog] Add missing changelog entries

[sachinpkale]

Description

Added missing changelog entries for #5804 and #5854

Issues Resolved

NA

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.

[sachinpkale]

Cancelling this PR as the entries are added as part of #6400

[github-actions]

Gradle Check (Jenkins) Run Completed with:

• RESULT: UNSTABLE ❕
• TEST FAILURES:

      1 org.opensearch.cluster.allocation.AwarenessAllocationIT.testThreeZoneOneReplicaWithForceZoneValueAndLoadAwareness

• URL: https://build.ci.opensearch.org/job/gradle-check/11495/
• CommitID: 134153e
  Please review all flaky tests that succeeded after retry and create an issue if one does not already exist to track the flaky failure.