Vulkan: Fix UtilsVk clear in non-zero subpass Mid-render-pass clears (through UtilsVk) run on the current subpass, which in the presence of multisampled-render-to-texture unresolve would be subpass 1. The graphics pipeline for that draw call should set the correct subpass index. Bug: angleproject:4836 Change-Id: Iba4a03ea96a63b0f5d09c27e5283ff8a8b534e05 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2441509 Commit-Queue: Shahbaz Youssefi <syoussefi@chromium.org> Reviewed-by: Shahbaz Youssefi <syoussefi@chromium.org> Reviewed-by: Jamie Madill <jmadill@chromium.org>