Android OS is the most essential part to make Android phones operate. It does cost Google a lot of money to make, yet it gives phone manufacturers licenses for cheap, just to make phones cheap enough so that users chose them over iPhones. Google wants it so bad they are willing to lose a lot of money now hoping it will pay off in future when everyone has Androids. Apple (and Microsoft) who cannot use this model (they don't dominate in ads or search markets) obviously don't like this. How would you feel if you were Apple? So they will try to use patents to make Android licenses more expensive. I hope I explained it well this time.
P.S. I don't know what is the right response to dumping. With physical goods it's easy to prove. With software much harder. This does not mean dumping prices on phone OS software to kill competition is nice. Apple and MS are just using what they can within legal means. Google did not play it nice with them - why they should be nice to Google?