Bug: skia:10369
Add SkEncodeImageWithNDK, mirroring the CG and WIC versions, for
encoding with the NDK APIs added to R.
Rename SK_ENABLE_NDK_DECODING to SK_ENABLE_NDK_IMAGES and use it for
both encoding and decoding.
Move code for converting to/from NDK types into a common location.
Update encode_platform.cpp to use NDK encoding APIs when available and
to use both types of webp (lossy and lossless). Add tests specifically
for the new implementation.
Update NdkDecodeTest to use ToolUtils::equal_pixels for comparing
pixels.
Change-Id: Ic62f89af27372ccce90b8e028e01c388a135a68c
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/308800
Commit-Queue: Leon Scroggins <scroggo@google.com>
Reviewed-by: Mike Klein <mtklein@google.com>
