Support all formats for BitmapFactory.Options.inBitmap

bug:9194265

Instead of using custom code in skia to avoid allocations, use a
custom allocator that reuses the allocations from the inBitmap.

In order to avoid inconsistent state, the decode is done in a
separate bitmap and swapped into the existing native bitmap.

Eventually, we'd like to support inScaled=true completely avoiding
java allocations.

Change-Id: Ic4a2f2373b100a80a32c1cdebb7bcb726711c8a7