[EuiSelectable] Fix focus management bug

[myasonik]

Summary

Fixes #4128 and fixes #4147

1000 points to @chandlerprall for helping hunt down this fix

Checklist

• Check against all themes for compatibility in both light and dark modes
• Checked in mobile
• Checked in Chrome, Safari, Edge, and Firefox
• Props have proper autodocs
• Added documentation
• Checked Code Sandbox works for the any docs examples
• Added or updated jest tests
• Checked for breaking changes and labeled appropriately
• Checked for accessibility including keyboard-only and screenreader modes
• A changelog entry exists and is marked appropriately

[kibanamachine]

Preview documentation changes for this PR: https://eui.elastic.co/pr_4152/

[myasonik]

jenkins test this

[kibanamachine]

Preview documentation changes for this PR: https://eui.elastic.co/pr_4152/

[cchaos]

Has anyone also verified that this fixes the issue in Kibana?

[myasonik]

@cchaos Confirmed in Kibana this PR solves the issues over there. Good call.

[kibanamachine]

Preview documentation changes for this PR: https://eui.elastic.co/pr_4152/

[chandlerprall]

Small changelog nit, otherwise this LGTM

[cchaos]

Thanks for the quick fix @myasonik ! Tested on the docs site, and the implementation where I saw it before is fixed now. Just a comment about the CL.

@chandlerprall Should this get a backport for Kibana 7.10?

[chandlerprall]

@chandlerprall Should this get a backport for Kibana 7.10?

Works for me, seems worth getting ahead of instead of waiting for someone to notice & ask.

[kibanamachine]

Preview documentation changes for this PR: https://eui.elastic.co/pr_4152/