Set the animation type to float/int even if caller skips ofFloat/ofInt s...

...tatic constructors.

I spent some time trying to figure out how Android is calling ObjectAnimator without ofFloat and ofInt (checked all the other static and public constructors) and got nowhere. However, I was bumping in to an exception with a test that happened to deal with a FragmentTransaction animation.

The exception was that setAlpha(null) was not a valid method and it happened because the Shadow didn't know what type of values were in use.