Revert "Add an SkImageGenerator that uses NDK APIs"

This reverts commit cfef980939de1c1f6e21a43b16423f0912e87074.

Reason for revert: Breaking Google3 roll

Original change's description:
> Add an SkImageGenerator that uses NDK APIs
> 
> Bug: skia:10369
> Bug: skia:10371
> 
> This will allow Skia clients developing for Android 11+ to rely on
> Android's NDK APIs for decoding, which will allow them to decode
> without including their own decoding libraries (e.g. libjpeg-turbo).
> Using these APIs also provides support for static HEIF images.
> 
> Run ImageGenSrc in kPlatform_Mode on Android to verify decoding
> visually.
> 
> Add tests and a grayscale png.
> 
> Update some test bots running Android R to specify ndk_api so they will
> run the new code.
> 
> Change-Id: Ica782339b2414d472ede0b61729a127ce41892a5
> Reviewed-on: https://skia-review.googlesource.com/c/skia/+/305689
> Reviewed-by: Mike Klein <mtklein@google.com>
> Commit-Queue: Leon Scroggins <scroggo@google.com>

TBR=djsollen@google.com,mtklein@google.com,scroggo@google.com,brianosman@google.com,reed@google.com

Change-Id: Ifed506a76a0ff5903d101c1bf7330d319b8376a6
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: skia:10369
Bug: skia:10371
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/308180
Reviewed-by: Leon Scroggins <scroggo@google.com>
Commit-Queue: Leon Scroggins <scroggo@google.com>
12 files changed