Although nothing has been directly mentioned, it's obvious this is Google sticking up for Android device makers like Samsung and sending a message straight to Apple HQ. A message that quite clearly reads: "If you're going to sue our third party vendors that support Android and abuse the patent system against them, we're going to show you what it feels to be sued"
I doubt this move is about money, but definitely just sending a message to Apple. Each and every day Apple is starting to become more like a mid-nineties Microsoft and we all know how that worked out...