There is big competition in cloud computing so AWS is priced according to market rates. I seriously doubt AWS profit is significant enough to influence the rest of Amazon in way that would be considered monopoly abuse. Amazon's purchase of Whole Foods did not result in WF reducing prices (as was expected) to uncut other grocers in that market.
> Google is dumping in adjacent areas of tech - giving away Android for free, for example.
That ship has sailed; Google effectively eliminated the market for mobile operating systems and Microsoft could basically no longer sell Windows Mobile. But the open-sourcing of Android has led to direct competition as well -- Amazon runs a completely Google-free version of Android on their products.