Remove BaseGameActivity from TBMPSkeleton, TrivialQuest2, and TypeANumber

No other changes, just a lot of boilerplate to get rid of BGA for each of these three samples.

One sample is changed in each commit, if that makes for easier reviewing.

@claywilkinson 
@gguuss 
That's a no-op in the FragmentActivity/Activity super class, but will add it just for good form (maybe a future Android version will have something in there).