[7.17](backport #29966) Add the Elastic product origin header when talking to Elasticsearch or Kibana.

[mergify]

This is an automatic backport of pull request #29966 done by Mergify.
Cherry-pick of 5f3dd3e has failed:

On branch mergify/bp/7.17/pr-29966
Your branch is up to date with 'origin/7.17'.

You are currently cherry-picking commit 5f3dd3e39d.
  (fix conflicts and run "git cherry-pick --continue")
  (use "git cherry-pick --skip" to skip this patch)
  (use "git cherry-pick --abort" to cancel the cherry-pick operation)

Changes to be committed:
	new file:   libbeat/common/productorigin/productorigin.go
	modified:   libbeat/esleg/eslegclient/connection.go
	modified:   libbeat/esleg/eslegclient/connection_test.go
	modified:   metricbeat/module/elasticsearch/metricset.go

Unmerged paths:
  (use "git add/rm <file>..." as appropriate to mark resolution)
	deleted by us:   metricbeat/module/kibana/settings/settings.go
	both modified:   metricbeat/module/kibana/stats/stats.go
	both modified:   metricbeat/module/kibana/status/status.go

To fix up this pull request, you can check it out locally. See documentation: https://docs.github.com/en/github/collaborating-with-pull-requests/reviewing-changes-in-pull-requests/checking-out-pull-requests-locally

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• Start Time: 2022-01-25T18:05:05.859+0000

• Duration: 127 min 0 sec

• Commit: 39d6a05

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Test	Results
Failed	0
Passed	55227
Skipped	5322
Total	60549

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