Vulkan: Add host-image-copy usage to images when optimal The change currently doesn't actually copy on host, but prepares the image for it. Bug: angleproject:8341 Change-Id: I4458712dca46ef9872020e158a3f902e94f5eb93 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/4856146 Reviewed-by: Yuxin Hu <yuxinhu@google.com> Commit-Queue: Shahbaz Youssefi <syoussefi@chromium.org> Reviewed-by: Charlie Lao <cclao@google.com>