MDC List: Checkbox doesn't toggle when rendered inside list item

[abhiomkar]

Steps to reproduce:

1. Place checkbox inside mdc list item.
2. Make sure to add label element that is mapped to checkbox input (using label, for attribute).
3. Click on the label text, the checkbox is toggled twice.

Reproducible example on stackblitz.

Actual behaviour:

The checkbox should be toggled only once. Works fine when clicked on the area that is not checkbox and label element.

[williamernest]

We could potentially fix this quickly by adding pointer-events: none to label, input[type="checkbox"] elements inside of mdc-list-item elements.

[kfranqueiro]

Closed via #4055