bug(MatFormField):MatFormField suffix and prefix are NOT aligned with floating placeholder - even on DEMO PAGE

[Antoniossss]

Reproduction

got to https://material.angular.io/components/form-field/overview#prefix--suffix

Prefix and suffix of second example is not aligned with floating placeholder (when it is not floating)

Expected Behavior

Everything to be alligned

Actual Behavior

Environment

Angular demo page for 11.1.1

[crisbeto]

I think that in general the new form field appearances aren't really made for text-based prefixes. We should either remove those examples or switch them to icons.