Add documentation for known issue with use of custom codecs on version 2.7.0

[dreamer-89]

Description

Adds known bug related with usage of custom codecs in OpenSearch 2.7.0 for segment replication enabled indices.

Issues Resolved

Fixes #4194

Checklist

• By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license and subject to the Developers Certificate of Origin.
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[dreamer-89]

@hdhalter @Naarcha-AWS : Can you please review this change ?

[dreamer-89]

@Naarcha-AWS : As the bug was impacting 2.7.0 only and was fixed in 2.7.1+, I think we don't need backport to 2.11 ?

[dreamer-89]

@Naarcha-AWS @hdhalter : Can you please merge this change

[opensearch-trigger-bot]

The backport to 2.7 failed:

The process '/usr/bin/git' failed with exit code 128

To backport manually, run these commands in your terminal:

# Fetch latest updates from GitHub
git fetch
# Create a new working tree
git worktree add ../.worktrees/backport-2.7 2.7
# Navigate to the new working tree
pushd ../.worktrees/backport-2.7
# Create a new branch
git switch --create backport/backport-5863-to-2.7
# Cherry-pick the merged commit of this pull request and resolve the conflicts
git cherry-pick -x --mainline 1 f632991770d0647cf41155d444f8858da9d3320e
# Push it to GitHub
git push --set-upstream origin backport/backport-5863-to-2.7
# Go back to the original working tree
popd
# Delete the working tree
git worktree remove ../.worktrees/backport-2.7

Then, create a pull request where the base branch is 2.7 and the compare/head branch is backport/backport-5863-to-2.7.