Scaling (Animated)VectorDrawable inside ImageView

Before, the VectorDrawable is behaving like BitmapDrawable inside a ImageView,
and it can be blurry due to scaling.
Now apply the scaling information to the cached bitmap, then the size of bitmap
will match the ImageView's screen size. Therefore, no blurry any more.

b/18185626

Change-Id: I979cef3b5178a9bd37ee6cc776df3361ca47c803