Vulkan: Boilerplate for vkCmdNextSubpass Bug: angleproject:4881 Change-Id: I5c46c07e8c7865ef2bfd8aff0d3f8b5ba3ecd750 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2399181 Reviewed-by: Shahbaz Youssefi <syoussefi@chromium.org> Reviewed-by: Courtney Goeltzenleuchter <courtneygo@google.com> Commit-Queue: Shahbaz Youssefi <syoussefi@chromium.org>