Fix bug with layout animations when apps are auto-scaled.

The pivot points in RotateAnimation and ScaleAnimation are in pixel coordinates. When an app is being autoscaled, these values are incorrect and should be adjusted for the current scale factor. The fix adds API to Animation to allow ViewGroup to pass in the scaling factor.

Change-Id: I978c48f9b5aea6760148435e74e1a8d49e2f785d