interestfor cascade issue

[bakura10]

Hello,

I've been trying to use the new interestfor feature, but found a subtle edge case that seems to have been overlooked by the spec. You can reproduce the issue here: https://codepen.io/bakura10/pen/RNavdPL

As you can see from this example, the first command open a dialog which automatically move the focus to the first focusable element. If this element itself also has an interestfor attribute, then the interest listener will be called, even though there is technically no interest in the button (it is just focused automatically due to the very nature of dialog).

This is a frequent situation when using nested menu. Please note that it seems that native popover does not suffer this issue, but as we have a hard requirement to support iOS 15, we can't use popover for now.

Thanks!