Add group-by to APM Latency threshold rule

[benakansara]

Summary

Resolves #152990

Checklist

• Any text added follows EUI's writing guidelines, uses sentence case text and includes i18n support
• Unit or functional tests were updated or added to match the most common scenarios

[kibana-ci]

💛 Build succeeded, but was flaky

• Buildkite Build
• Commit: e4f2a6d

Failed CI Steps

• APM Cypress Tests #3

Metrics [docs]

Module Count

Fewer modules leads to a faster build time

id	before	after	diff
apm	1275	1276	+1

Async chunks

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

id	before	after	diff
apm	3.4MB	3.4MB	+1.8KB

Page load bundle

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

id	before	after	diff
apm	32.0KB	32.0KB	+1.0B

Unknown metric groups

ESLint disabled line counts

id	before	after	diff
securitySolution	432	435	+3

Total ESLint disabled count

id	before	after	diff
securitySolution	512	515	+3

History

• 💛 Build #119605 was flaky 6b83cf4
• 💔 Build #119541 failed 92011cb
• 💔 Build #119481 failed 9de9781
• 💔 Build #119450 failed ee48316
• 💔 Build #119425 failed 408877a
• 💔 Build #119180 failed b20abe9

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

cc @benakansara