fix(modal): ariaLabel and role are inherited when set via htmlAttributes (#29099)

Issue number: Internal

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## What is the current behavior?
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Modal inherits `aria-label` and `role` to an element inside of its
Shadow DOM. However, this only works if developers set the attributes on
the host element directly. Setting the attributes via the
`htmlAttributes` property causes the attributes to be set on the host
and not inherited.

## What is the new behavior?
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this PR. -->

- `aria-label` and `role` are inherited even when set using
`htmlAttributes`.

## Does this introduce a breaking change?

- [ ] Yes
- [x] No

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## Other information

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screenshots of how the component looks before and after the change. -->

Dev build: `7.7.4-dev.11709154993.1b49c313`