fix(ngAria): do not set aria attributes on input[type="hidden"]

[Narretz]

This fixes a error found by @edclements using the Google Accessibility Developer Tools audit.
Input fields of type hidden shouldn't have aria attributes.
https://www.w3.org/TR/html-aria/#allowed-aria-roles-states-and-properties-1

Closes #15113

What kind of change does this PR introduce? (Bug fix, feature, docs update, ...)

What is the current behavior? (You can also link to an open issue here)
aria attributes added to input type hidden

What is the new behavior (if this is a feature change)?
Not anymore.

Does this PR introduce a breaking change?
I would say not actually, because the previous behavior didnt follow the spec and I can'T see why anyone would rely on this behavior. It was marked as breaking change in #15113, though

Please check if the PR fulfills these requirements

• The commit message follows our guidelines
• Fix/Feature: Docs have been added/updated
• Fix/Feature: Tests have been added; existing tests pass

Other information:

Rebased and updated version of #15113

[Narretz]

Thanks @gkalpak . Just to clarify, are you okay with thi going into 1.6.x too? Because I currently have not added a BC notice.

[gkalpak]

Hm...you are sneaky 😛
Technically, it is a fix, but it can theoretically break a test. Probably safest to go into 1.7, but I'm on the fence 😃
(Maybe @mgol has a stronger opinion - he added the needs: breaking change to the original PR 😁)

[Narretz]

@gkalpak you said it was a BC and that you would add the BC label: 😛 #15113 (comment)

[gkalpak]

But I didn't 😛
I still mostly agree with myself though (always a good sign 😛).
It is theoretically a BC and I would rather treat it as such. (But if you feel otherwise - and @mgol doesn't have a strong opinion in favor of a BC - I can live with getting it into 1.6.x (as I said in my original comment anyway 😛).)

[Narretz]

But I didn't

Because you forgot 😛
I'll add a BC notice - it's such a small change, and I guess screen readers already ignore hidden inputs, so I doubt this really affects anyone as is