Move vulkan layout helpers from GrVkMemory to GrVkImage.

Bug: skia:
Change-Id: Iebcf5844a0b469dea1e96e351f91239ff512f708
Reviewed-on: https://skia-review.googlesource.com/129934
Reviewed-by: Jim Van Verth <jvanverth@google.com>
Commit-Queue: Greg Daniel <egdaniel@google.com>
6 files changed