Vulkan: Don't sync VAOs after BufferSubData calls. We still need to syncState after buffers that contain converted attributes are updated. Includes a perf regression test. Bug: angleproject:6371 Change-Id: I54227fc43e7b3fe79072da7783dab0177ccb0486 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/3182706 Commit-Queue: Jamie Madill <jmadill@chromium.org> Reviewed-by: Tim Van Patten <timvp@google.com> Reviewed-by: Shahbaz Youssefi <syoussefi@chromium.org>