fix(mdUtil): change wrapper width for disableScrollAround

[mchmielarski]

This commit remove problems with mdSelect component in dialogs
for focus state

[ThomasBurleson]

@rschmukler - reasonable change to disableScrollAround() ?

[ThomasBurleson]

@rschmukler - you have been working with Select and scrolling. Is this PR still viable ?

[rschmukler]

@ThomasBurleson given the changes that have gone in to $mdSelect it's no longer necessary. @mchmielarski thank you for your efforts. There were so many issues around the new disableScroll that I wanted to handle multiple issues at once. Apologies on the lack of responsiveness on my part.