ngAria: tabIndex unnecessarily added to buttons & other interactive elements

[marcysutton]

As it is currently written, ngAria is a bit too generous about adding tabindex="0" to elements. It adds the attribute to any element with ngModel or ngClick without checking whether it should actually do that. This includes buttons, inputs and other elements that might not need it. Adding unnecessary tabindex contributes to code bloat and is generally a poor practice.

[thebuilder]

This is still an issue on Radio buttons, where it sets tabindex to -1. The selected radio button gets 0, but this still prevents you from tabbing to the other radio buttons.
See: #12492 (comment)