Radios should activate ripple when their corresponding label is pressed

[traviskaufman]

What MDL Version are you using? (please be specific, e.g. major.minor.patch)

v2 @ master

What browser(s) is this bug affecting (including version)?

all

What OS (and version) are you using?

OS X El Capitan

What are the steps to reproduce the bug? Can you create a plunker/codepen/jsfiddle which reproduces it?

1. Type npm run dev and navigate to http://localhost:8080/radio.html
2. Click on a label for a radio

What is the expected behavior?

The ink ripple should activate

What is the actual behavior?

Only the focus ripple activates

Any other information you believe would be useful?

This is due to the fact that isSurfaceActive is always set to false in the radio's ripple adapter. Instead, we need to set it conditionally based on whether or not the label is being interacted with.

[sfdexter]

Superceded by material-components/material-components-web#9