Bug 1023714 - [vertical homescreen] Cancel button is not localized after a long press on the homescreen

https://bugzilla.mozilla.org/show_bug.cgi?id=1023714

Gaia-try: https://tbpl.mozilla.org/?tree=Gaia-Try&showall=1&rev=0bb3b4d9ab81
Thanks guys, going to leave this in for now as we want a nice third party developer experience with these. Once we've fully figured out localization in web components, we can certainly remove it.