Vulkan: Protect OneOff commands recording with pool mutex Bug: angleproject:384940864 Change-Id: I518c54ae4b0fc5da0e58d330f8c531bc8d65529e Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/6108843 Commit-Queue: Igor Nazarov <i.nazarov@samsung.com> Reviewed-by: Shahbaz Youssefi <syoussefi@chromium.org> Reviewed-by: Charlie Lao <cclao@google.com>