Revert "Experimental: Add R_16 and RG_1616 to Ganesh"

This reverts commit 93d0146dc6a1a94fa1dca1c05272f1f46e777ddf.

Reason for revert: revertting so we can revert previous change

Original change's description:
> Experimental: Add R_16 and RG_1616 to Ganesh
> 
> This is to support the P016 and P010 YUV formats. Initially, only Vulkan and GL support these formats.
> 
> Change-Id: Ie9609e59c12528079f8d379359ddb9bac85b6a29
> Reviewed-on: https://skia-review.googlesource.com/c/skia/+/218546
> Commit-Queue: Robert Phillips <robertphillips@google.com>
> Reviewed-by: Greg Daniel <egdaniel@google.com>

TBR=egdaniel@google.com,robertphillips@google.com

Change-Id: I00e1bf32404983b09f0933b2a9d65aa40a5ee754
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/218959
Reviewed-by: Greg Daniel <egdaniel@google.com>
Commit-Queue: Greg Daniel <egdaniel@google.com>
21 files changed