[ML] Retains created_by setting when exporting anomaly detection jobs

[jgowdyelastic]

When exporting an anomaly detection job, it would be useful if the original created_by property was not removed from the job config.

Related to #167021 (comment)
Related PR #88898

[elasticmachine]

Pinging @elastic/ml-ui (:ml)

[peteharverson]

Tested and LGTM

[qn895]

Code LGTM 🎉

[kibana-ci]

💛 Build succeeded, but was flaky

• Buildkite Build
• Commit: 98bd77e

Failed CI Steps

• FTR Configs #22

Test Failures

• [job] [logs] FTR Configs #22 / maps app mvt scaling "after all" hook in "mvt scaling"
• [job] [logs] FTR Configs #22 / maps app mvt scaling filtering applyGlobalQuery: true, applyGlobalTime: true, applyForceRefresh: true "after all" hook for "should update MVT URL when refresh clicked"
• [job] [logs] FTR Configs #22 / maps app mvt scaling filtering applyGlobalQuery: true, applyGlobalTime: true, applyForceRefresh: true should update MVT URL when refresh clicked

Metrics [docs]

Async chunks

Total size of all lazy-loaded chunks that will be downloaded as the user navigates the app

id	before	after	diff
ml	3.5MB	3.5MB	+11.0B

Page load bundle

Size of the bundles that are downloaded on every page load. Target size is below 100kb

id	before	after	diff
ml	76.0KB	76.0KB	+23.0B

History

• 💔 Build #162930 failed cef6705
• 💚 Build #162728 succeeded 2b9e0a5
• 💛 Build #162579 was flaky da86d3b

To update your PR or re-run it, just comment with:
@elasticmachine merge upstream

cc @jgowdyelastic