Use ImageDecoder for NinePatchDrawable and BitmapDrawable

Don't scale NinePatchDrawable if bitmap has no density.
Fixed bugs around density and input streams.

Update PointerIcon to account for the fact that BitmapDrawable no longer
scales its Bitmap up at decode time. PointerIcon now handles the
scaling. This is necessary because PointerIcon never draws its Bitmap.
Instead, native code uses the Bitmap's internal SkBitmap without
accounting for density.

Test: Ran CTS:
- CtsUiRenderingTestCases
- CtsGraphicsTestCases
- CtsViewTestCases

Change-Id: I030b4bb89c66b0102ccea2d85f5271197558d14e