yongzh has received a relicense for gpSP by me, the sole copyright holder of the source he forked off of (he isn't using any code from any of the other forks). So Gameboid isn't violating any license agreements. It getting pulled is either at Google's discretion due to complaints against the owner in general or, more likely, Nintendo pressuring him.
Remember, Google makes money off of his sales too. I doubt they'd remove emulators that didn't directly correlate to any particular person's specific complaint (nor would they take a complaint from some random non-copyright holder seriously). Nintendo, on the other hand..