The new animation package's reliance on the old Interpolator interface (in
android.view.animation) was an eyesore. Adding TimeInterpolator, and having the
old Interpolator interface extend it, allows the new Animator classes to break
the tie to the older animation package completely. However, developers can still
use the older Interpolator-based classes, such as AccelerateInterpolator,
because they all implicitly extend the new TimeInterpolator class.
Change-Id: I41132fa56167ba564f4839113289114d0ea31a92
e0ee2e9f31