[Observability:Rules:Create page]Inaccessible confirmation button for rule name

[L1nBra]

Description
All interactive elements has to be accessible for users using only keyboard as well.

Preconditions
Observability -> Alerts -> Rules -> Create page.

Steps to reproduce

1.Navigate to rule name.
2.Press Enter.
3.Press Tab few times.
4.Observe page.

Screen recording
https://github.com/user-attachments/assets/c627b4e5-f82d-47cc-9158-808971ac4a3c

Actual Result

• When user press Tab, focus is missing from the page. When user press Tab one more time - focus is on rule name.

Expected Result

• When user press Tab key, focus is on confirmation button and user can confirm change of the rule name.

Meta Issue

Kibana Version: 8.17.0-SNAPSHOT

OS: Windows 11 Pro

Browser: Chrome Version 131.0.6778.140 (Official Build) (64-bit)

WCAG or Vendor Guidance (optional)

• Understanding SC 2.1.1: Keyboard (Level A)(https://www.w3.org/WAI/WCAG22/Understanding/keyboard.html)
• Understanding SC 2.4.7: Focus Visible (Level AA)(https://www.w3.org/WAI/WCAG22/Understanding/focus-visible.html)

Related to: https://github.com/elastic/kibana-team/issues/1254

[elasticmachine]

Pinging @elastic/kibana-accessibility (Project:Accessibility)