Fix broken Nginx Integration data volume panel

[Swiddis]

Description

The current Nginx integration has a data volume panel with a misconfigured field, which led to nonsense results when trying with sample data. This PR is a quick update to the config to fix it.

We also remove a redundant Nginx version, since there isn't much reason to have multiple versions of the integration live at this stage.

Issues Resolved

N/A

Check List

• New functionality includes testing.
  • All tests pass, including unit test, integration test and doctest
• New functionality has been documented.
  • New functionality has javadoc added
  • New functionality has user manual doc added
• Commits are signed per the DCO using --signoff

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.

[codecov]

Codecov Report

Merging #787 (8055ffa) into main (bfada80) will decrease coverage by 0.01%.
Report is 2 commits behind head on main.
The diff coverage is n/a.

❗ Current head 8055ffa differs from pull request most recent head 422c596. Consider uploading reports for the commit 422c596 to get more accurate results

@@            Coverage Diff             @@
##             main     #787      +/-   ##
==========================================
- Coverage   43.66%   43.65%   -0.01%     
==========================================
  Files         312      312              
  Lines       18587    18587              
  Branches     4528     4479      -49     
==========================================
- Hits         8116     8115       -1     
- Misses       9921    10430     +509     
+ Partials      550       42     -508     

Flag	Coverage Δ
dashboards-observability	43.65% <ø> (-0.01%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

see 81 files with indirect coverage changes

[opensearch-trigger-bot]

The backport to 2.x failed:

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

To backport manually, run these commands in your terminal:

# Navigate to the root of your repository
cd $(git rev-parse --show-toplevel)
# Fetch latest updates from GitHub
git fetch
# Create a new working tree
git worktree add ../.worktrees/dashboards-observability/backport-2.x 2.x
# Navigate to the new working tree
pushd ../.worktrees/dashboards-observability/backport-2.x
# Create a new branch
git switch --create backport/backport-787-to-2.x
# Cherry-pick the merged commit of this pull request and resolve the conflicts
git cherry-pick -x --mainline 1 7f5cfe7d0d253533db1e2f2447940ad009942fa3
# Push it to GitHub
git push --set-upstream origin backport/backport-787-to-2.x
# Go back to the original working tree
popd
# Delete the working tree
git worktree remove ../.worktrees/dashboards-observability/backport-2.x

Then, create a pull request where the base branch is 2.x and the compare/head branch is backport/backport-787-to-2.x.

[opensearch-trigger-bot]

The backport to 2.9 failed:

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

To backport manually, run these commands in your terminal:

# Navigate to the root of your repository
cd $(git rev-parse --show-toplevel)
# Fetch latest updates from GitHub
git fetch
# Create a new working tree
git worktree add ../.worktrees/dashboards-observability/backport-2.9 2.9
# Navigate to the new working tree
pushd ../.worktrees/dashboards-observability/backport-2.9
# Create a new branch
git switch --create backport/backport-787-to-2.9
# Cherry-pick the merged commit of this pull request and resolve the conflicts
git cherry-pick -x --mainline 1 7f5cfe7d0d253533db1e2f2447940ad009942fa3
# Push it to GitHub
git push --set-upstream origin backport/backport-787-to-2.9
# Go back to the original working tree
popd
# Delete the working tree
git worktree remove ../.worktrees/dashboards-observability/backport-2.9

Then, create a pull request where the base branch is 2.9 and the compare/head branch is backport/backport-787-to-2.9.