[Search:AppSearch:Engines:Schema page]Add a new field modal dialog missing title from announcement

[L1nBra]

Description Dialog modal visible title should be announced for the users, especially using assistive technology to know what dialog modal opened.

Preconditions Stateful App Search -> Engines -> Schema page is opened. Engine is added. Use Screen Reader (NVDA).

Steps to reproduce

1.Using only keyboard navigate to Create a schema field button by pressing Tab key. 2.Press Enter. 3.Observe screen reader.

UI elements + NVDA Speech Viewer

Actual Result

• Dialog modal is announced only as "dialog".

Expected Result

• Dialog is announced with the title "Add a new field dialog".

Meta Issue

Kibana Version: 8.17.0-SNAPSHOT

OS: Windows 11 Pro

Browser: Chrome Version 130.0.6723.70 (Official Build) (64-bit)

Screen reader: NVDA

WCAG or Vendor Guidance (optional)

• Understanding SC 4.1.2: Name, Role, Value (Level A)(https://www.w3.org/WAI/WCAG22/Understanding/name-role-value.html)

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

[elasticmachine]

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