Use the new GrMSAAAttachment class in vulkan.

Instead of creating internal msaa VkImages for vulkan render targets we
now get a GrMSAAAttachment from the resource provider to use instead.
As of now only one GrVkRenderTarget can hold a ref to an msaa attachment
at a time.

Bug: skia:10830
Change-Id: I361a1687f10e047a5b61228f861326f2b1418f06
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/320272
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Greg Daniel <egdaniel@google.com>
6 files changed