Revert "Add support for RGB config to Vulkan."

This reverts commit a8b20a1af7a529a8ecdb0cccc5012fa79fed2605.

Reason for revert: breaking some bots

Original change's description:
> Add support for RGB config to Vulkan.
> 
> This adds support for RGB, but from investigating, most desktops don't
> support RGB at all, and on Android it is usually support as a linear
> format and not necessarily an optimal one. So until we get better support
> for linear formats this CL doesn't necessarily add more feature support to
> our vulkan backend.
> 
> Bug: skia:8349
> Change-Id: I1066ddafa660a1ef1d90dbf3e127e067d6132d45
> Reviewed-on: https://skia-review.googlesource.com/156600
> Commit-Queue: Greg Daniel <egdaniel@google.com>
> Reviewed-by: Robert Phillips <robertphillips@google.com>

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

Change-Id: Ibb7b67c36a1dbcf0d670e0ff293003eac23b5ac4
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: skia:8349
Reviewed-on: https://skia-review.googlesource.com/156940
Reviewed-by: Greg Daniel <egdaniel@google.com>
Commit-Queue: Greg Daniel <egdaniel@google.com>
7 files changed