Left Icons on Inputs have extra underline effect (1.0.0 beta)

[emman27]

Steps to reproduce

Place an input with left icon over any colored element

Which browser?

Chrome 62, Ubuntu 16.04

What is expected?

Clean icon similar to 0.8

What is actually happening?

The icon shows an oddly sized underline. This doesn't look so awful on this documentation site, but check it out on a toolbar.

[Pwntus]

This line seems to be the cause.

@include md-theme-property(background-color, background-variant);

background-variant should yield the same color as the background behind the md-field.