Vulkan: Fix image copies with renderbuffers When doing an EXT_copy_image copy, renderbuffers were being recreated due to a mismatch in sample count values. Bug: angleproject:3593 Test: dEQP-GLES31.functional.copy_image.*renderbuffer* Change-Id: Ic6b85ea098ab6382b56520b1ca6b76ac25801b54 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2538076 Reviewed-by: Shahbaz Youssefi <syoussefi@chromium.org> Reviewed-by: Jamie Madill <jmadill@chromium.org> Commit-Queue: Shahbaz Youssefi <syoussefi@chromium.org>