refactor(slide-toggle): switch to fakeAsync tests (#10506)
refactor(slide-toggle): switch to fakeAsync tests (#10506)

Switches all of the slide toggle unit tests to run in the `fakeAsync` zone, rather than `async`, in order to make them cleaner and more reliable.
andrewseguin/material2,DevVersion/material2,josephperrott/material2,ppham27/material2,amcdnl/material2,andrewseguin/material2,ppham27/material2,josephperrott/material2,ppham27/material2,DevVersion/material2,andrewseguin/material2,amcdnl/material2,tinayuangao/material2,Jefiozie/material2,crisbeto/material2,tinayuangao/material2,ppham27/material2,tinayuangao/material2,crisbeto/material2,angular/components,amcdnl/material2,andrewseguin/material2,angular/components,amcdnl/material2,jelbourn/material2,mmalerba/material2,jelbourn/material2,Jefiozie/material2,tinayuangao/material2,mmalerba/material2,jelbourn/material2,josephperrott/material2,josephperrott/material2,angular/components,mmalerba/material2,crisbeto/material2,tinayuangao/material2,Jefiozie/material2,DevVersion/material2,DevVersion/material2,crisbeto/material2,mmalerba/material2,angular/components,Jefiozie/material2,ppham27/material2,josephperrott/material2,jelbourn/material2,Jefiozie/material2,amcdnl/material2,andrewseguin/material2,jelbourn/material2,DevVersion/material2,mmalerba/material2