The really big unaddressed question in this post is whether Google actually does have to defend Android. After all, $10 per handset is nothing like as much as the cost of developing, maintaining and supporting your own smartphone OS. We're not talking feature phone here, this is a sizeable piece of sophisticated software that is in competition (primarily) with iOS. (Bear in mind that Apple can amortize its enormous development expense over a very large number of handsets!) I suppose you could argue that it gives MS some kind of an advantage with their OS but that rather ignores the investment MS had to make developing their OS.
I am certainly prepared to be persuaded that somehow fighting the patents in question is a life or death matter for Android but so far I haven't seen a convincing evidence that it's true.