fix(ui5-shellbar): acc findings fixed

[PetyaMarkovaBogdanova]

5) ShellBar (9 failing)

• Repeated continuum ARIA validity violations:
• Rule 281: aria-expanded not allowed on the flagged button host in these rendered cases.
• Rule 270: aria-required not allowed on the flagged switch host.
• Rule 736: dialog section without computable accessible name (missing dialog naming mechanism).
• Impacted tests include search-field scenarios, responsive/overflow behavior, and keyboard navigation checks.

Component	Issue	Not by spec	Good to have	Spec refs	Spec quote sentence	Coverage strength
ShellBar	Dialog without accessible name	Yes	No	ACC-253, ACC-264	"the dialog 'title' should be associated with the container having role=dialog using aria-labelledby"	Direct
ShellBar	Invalid aria-expanded/aria-required usage	Likely Yes	No	ACC-264	"aria-expanded=true/false with respect to showing state of dialog" and "aria-required must be set in the HTML form control (input)"	Direct

[ui5-webcomponents-bot]

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