Vulkan: Follow up fix and enable asyncCommandBufferReset flag This CL makes any follow up fix for crrev.com/c/4244823 and enables asyncCommandBufferReset feature flag. It changes CommandQueue::checkCompletedCommands only do the check and update mLastCompletedSerials. It makes async command processor thread always call checkCompletedCommands if mNeedCommandsAndGarbageCleanup is true so that we can clean up more garbages. This CL also makes garbage clean up always done in async thread even if asyncCommandBufferReset is disabled. Bug: b/255411748 Change-Id: I1d63aa9f1f565d81780a39c29b919da3dd5a68be Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/4264175 Commit-Queue: Charlie Lao <cclao@google.com> Reviewed-by: Shahbaz Youssefi <syoussefi@chromium.org> Auto-Submit: Charlie Lao <cclao@google.com>