[Flyout System] Set ownFocus=false in storybooks

[tsullivan]

Summary

Setting ownFocus=false in Flyout System storybooks where the user needs access to the underlying page to open additional flyouts into the Flyout System.

Why are we making this change?

This is a change that is needed for testing.

Screenshots #

Impact to users

Only developers testing the Flyout System will be impacted.

QA

Remove or strikethrough items that do not apply to your PR.

General checklist

• Browser QA
  • Checked in both light and dark modes
  • Checked in both MacOS and Windows high contrast modes
    • (emulate forced colors if you do not have access to a Windows machine.)
  • Checked in mobile
  • Checked in Chrome, Safari, Edge, and Firefox
  • Checked for accessibility including keyboard-only and screenreader modes
• Docs site QA
  • Added documentation
  • Props have proper autodocs (using @default if default values are missing) and playground toggles
  • Checked Code Sandbox works for any docs examples
• Code quality checklist
  • Added or updated jest and cypress tests
  • Updated visual regression tests
• Release checklist
  • A changelog entry exists and is marked appropriately.
  • If applicable, added the breaking change issue label (and filled out the breaking change checklist)
• Designer checklist
  • If applicable, file an issue to update EUI's Figma library with any corresponding UI changes. (This is an internal repo, if you are external to Elastic, ask a maintainer to submit this request)

[elasticmachine]

💚 Build Succeeded

• Buildkite Build
• Commit: bd6d398
• Documentation website
• Storybook

[elasticmachine]

💚 Build Succeeded

• Buildkite Build
• Commit: bd6d398

[tkajtoch]

LGTM