[filebeat][httpjson] Fix counter for number of published events

[r00tu53r]

What does this PR do?

Fixes a counter that tracks the number of processed and published events when handling responses for httpjson input.

Why is it important?

The total number of events sent to ES would be logged incorrectly.

Checklist

• My code follows the style guidelines of this project
• [ ] I have commented my code, particularly in hard-to-understand areas
• [ ] I have made corresponding changes to the documentation
• [ ] I have made corresponding change to the default configuration files
• [ ] I have added tests that prove my fix is effective or that my feature works
• I have added an entry in CHANGELOG.next.asciidoc or CHANGELOG-developer.next.asciidoc.

[elasticmachine]

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• Start Time: 2022-07-19T05:02:43.560+0000

• Duration: 77 min 1 sec

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Skipped	166
Total	2336

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[efd6]

It would be nice to have a test for this, but it's not critical.

[mergify]

This pull request is now in conflicts. Could you fix it? 🙏
To fixup this pull request, you can check out it locally. See documentation: https://help.github.com/articles/checking-out-pull-requests-locally/

git fetch upstream
git checkout -b fix/event-publish-counter upstream/fix/event-publish-counter
git merge upstream/main
git push upstream fix/event-publish-counter

[jsoriano]

I guess this could be merged? Could you please fix the conflicts in the changelog?

[elasticmachine]

Pinging @elastic/security-external-integrations (Team:Security-External Integrations)