For what it's worth, if you can show you were proving real value and not primarily getting just entertaintainment/training from Google, you could work this way for a period and sue Google for back wages. The courts in the U.S./California generally take minimum wages very seriously and case law has defined the exceptions quite narrowly. Even non-profits have been successfully sued for wages for "volunteer" labor.

It's also true basically all unpaid internships are illegal and interns can easily sue for back wages, FWIW.