fix(material/datepicker): unable to click datepicker toggle when form field is disabled (#25863)
fix(material/datepicker): unable to click datepicker toggle when form field is disabled (#25863)

We support the case where the form field is disabled, but the datepicker isn't. Currently this is broken, because MDC sets `pointer-events: none` on the entire form field when it is disabled. These changes add `pointer-events: auto` only on the toggle to enable clicking.
angular/components,crisbeto/material2,angular/components,crisbeto/material2,crisbeto/material2,angular/components,crisbeto/material2,angular/components