Airbnb just got a big cash infusion — and Google is one of its big investors. According to a report from Fortune, the company has raised $555 million at a $30 billion valuation, part of a desired $850 million round that it filed to raise last month. Google Capital and Technology Crossover Ventures led the deal, according to the Wall Street Journal. A person close to the company confirmed that Airbnb plans to file a form D this afternoon…