We've talked plenty about everything Google announced at its big hardware gala — particularly that Pixel 4 phone and the perplexing predicament Google finds itself facing as it tries to convince average phone-shoppers to give the gadget a go.There's one thing Google didn't announce at that fall event, though, and it might be the most important product of all — both in terms of its potential impact for Google, from a business perspective, and in terms of its relevance for those of us who use Android phones.