[8.0] Update to elastic/beats@4d7e91351f6e

[axw]

Needs elastic/beats#28671 to be backported to 8.0.

[apmmachine]

💚 Build Succeeded

the below badges are clickable and redirect to their specific view in the CI or DOCS

Expand to view the summary

Build stats

• Start Time: 2021-11-16T01:58:07.475+0000

• Duration: 43 min 3 sec

• Commit: a6c66da

Test stats 🧪

Test	Results
Failed	0
Passed	6014
Skipped	19
Total	6033

🤖 GitHub comments

To re-run your PR in the CI, just comment with:

• /test : Re-trigger the build.

• /hey-apm : Run the hey-apm benchmark.

• /package : Generate and publish the docker images.

• run elasticsearch-ci/docs : Re-trigger the docs validation. (use unformatted text in the comment!)

[mergify]

This pull request is now in conflicts. Could you fix it @axw? 🙏
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 update-beats-8.0 upstream/update-beats-8.0
git merge upstream/8.0
git push upstream update-beats-8.0