Revert "Restructure Metal utils for code sharing and to match Vulkan paths."

This reverts commit f7f7060ed3e4d383d19c084b1d815a69e5d6c543.

Reason for revert: Link issues with Google3

Original change's description:
> Restructure Metal utils for code sharing and to match Vulkan paths.
>
> Sets up a place to put shared code for YUVA.
>
> Bug: b/238756380
> Change-Id: I1108b638eb1359629c1b6268268f854a3c41aad9
> Reviewed-on: https://skia-review.googlesource.com/c/skia/+/650781
> Reviewed-by: Greg Daniel <egdaniel@google.com>
> Commit-Queue: Jim Van Verth <jvanverth@google.com>

Bug: b/238756380
Change-Id: I5ae0e21b0366bf58e1c320c0d01cdb30c4299ff1
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/651758
Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
Auto-Submit: Jim Van Verth <jvanverth@google.com>
34 files changed