[Stateful:Indices:Index mapping page] Edit field dialog error (callout) is not announced for screen reader users

[L1nBra]

Description All errors should be not only present for users to see them visually, but for users using assistive technology - they should be able to hear about them in order to fix them.

Preconditions Stateful Indices -> Index mapping page is opened. At least one field is added. Use Screen Reader (NVDA).

Steps to reproduce

1.Navigate to Edit button by pressing Tab key in Pending Fields section 2.Press Enter. 3.Delete text from Field name. 4.Delete text from Field type. 5.Navigate to Update button. 6.Press Enter. 7.Observe the page. 8.Observe screen reader announcement.

NVDA Speech Viewer + UI elements

Html snippet

Actual Result

• Error callout appears; even though first field with error looks as active one, when pressing Tab key - navigation goes from first element on the dialog; screen reader doesn't announce error (callout) after Update button, only the webpage title.

Expected Result

• First field with error should be interactive and focus should be present directly on it; screen reader announces the error (callout) after Update button.

Notes: Either role should be added with alert value or corresponding aria label (f.e.: aria-live = "assertive".)

Meta Issue

Kibana Version: 8.16.0-SNAPSHOT

OS: Windows 11 Pro

Browser: Chrome Version 129.0.6668.70 (Official Build) (64-bit)

Screen reader: NVDA

WCAG or Vendor Guidance (optional)

• Understanding SC 3.3.1: Error Identification (Level A)(https://www.w3.org/WAI/WCAG22/Understanding/error-identification.html)
• Understanding SC 2.4.3: Focus Order (Level A)(https://www.w3.org/WAI/WCAG22/Understanding/focus-order.html)

Related to: https://github.com/elastic/search-team/issues/8256

[elasticmachine]

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