Apple won't be able to stand up to Google directly as Android is open source. Claiming infringement on an open source product is incredibly hard, because its out in the open.
You can't say Google is maliciously copying Apple software if Google is open and honest about it.
Now if you were a proprietary software publisher that hid someone else's code away and tried to sell it for a profit, the patent holder would have a much clearer and stronger case. That's not the situation. Android is free and very public about what it is, so Apple can really only attack the numerous manufacturers that are attempting to profit from it, which also means that Apple has to prove a connection between the infringed material and the companies profits.
Amazon wont be sued by Apple over its use of android because it doesn't make a profit off of device sales only the media purchased with the device. This would be too hard for Apple to link together in a courtroom