Vulkan: Fix assertion when YUV image attached to resolve attachment When YUV image attached to resolve attachment, mSamples is 1. Righ now the code assumes resolve is a MSRT attachment, so it asserts mSamples>1. This CL adds a new API packYUVResolveAttachment so that we can assert properly for YUV and MSRT. Bug: b/223456677 Change-Id: Ib65fd3fe1e6561b85395cc27204bbd85c1f464c3 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/4942907 Commit-Queue: Charlie Lao <cclao@google.com> Reviewed-by: Chris Forbes <chrisforbes@google.com> Reviewed-by: Shahbaz Youssefi <syoussefi@chromium.org>