[Lens] Make Formula functional tests less flaky

[dej611]

Summary

Fixes (again) #102183

Adding some waiting time after the typing fixed the flaky behaviour - the editor schedules a text replacement as async task and sometimes it takes a bit longer than usual.

Here I've ran the lens formula suite with 100 agents: https://kibana-ci.elastic.co/job/kibana+flaky-test-suite-runner/1902/

Checklist

Delete any items that are not applicable to this PR.

• Any text added follows EUI's writing guidelines, uses sentence case text and includes i18n support
• Documentation was added for features that require explanation or tutorials
• Unit or functional tests were updated or added to match the most common scenarios
• Any UI touched in this PR is usable by keyboard only (learn more about keyboard accessibility)
• Any UI touched in this PR does not create any new axe failures (run axe in browser: FF, Chrome)
• If a plugin configuration key changed, check if it needs to be allowlisted in the cloud and added to the docker list
• This renders correctly on smaller devices using a responsive layout. (You can test this in your browser)
• This was checked for cross-browser compatibility

[elasticmachine]

Pinging @elastic/kibana-vis-editors (Team:VisEditors)

[jbudz]

Can we backport to 7.14+? Here's a recent failure:
https://buildkite.com/elastic/kibana-elasticsearch-snapshot-verify/builds/119#_

[dej611]

@elasticmachine merge upstream

[dej611]

Can we backport to 7.14+? Here's a recent failure:
buildkite.com/elastic/kibana-elasticsearch-snapshot-verify/builds/119#_

I see no harm in that. What do you think @stratoula @flash1293 ?

[stratoula]

Yes it is fine. For functional tests fixes it is safe to backport them in previous versions

[kibanamachine]

💚 Build Succeeded

• continuous-integration/kibana-ci/pull-request
• Commit: 245660b
• Storybooks Preview

Metrics [docs]

✅ unchanged

History

• 💚 Build #153875 succeeded 6fa99cd

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

[dej611]

Changed labels to enable backports to 7.14+

[mbondyra]

Code lgtm, not sure if it will help avoiding flakiness completely, but definitely will not harm anything!

[kibanamachine]

💚 Backport successful

Status	Branch	Result
✅	7.x
✅	7.14
✅	7.15

The backport PRs will be merged automatically after passing CI.