aria-hidden value can render incorrectly

Problem/Motivation

When using External Links along with the Domain module, which offers Domain Configuration, unexpected values are being rendered for things like aria-hidden.

Out of the box, External Links renders aria-hidden="false" just fine for the "Hide decorative icons from screen readers" configuration option.

However, when using Domain Configuration, this value is stored as 0 or 1, which results in an invalid property: aria-hidden="0".

Steps to reproduce

• Install Domain module
• Install External Link module
• Add path for External Links module in Domain Configuration UI
• Enable Domain Configuration for External Link
• Change a setting like "Hide decorative icons from screen readers."
• View the config setting in extlink.settings.yml: extlink_hide_icons: true
• View the config setting in domain.config.[domain].en.extlink.settings.yml: extlink_hide_icons: 1
• View an external link on the front end and see aria-hidden="1"

Proposed resolution

Could line 458 check the value rather than just outputting the value to prevent these cases? Something like iconElement.setAttribute('aria-hidden', drupalSettings.data.extlink.extHideIcons ? true : false);?