Vulkan: Move post submit code into a separate function This CL is mostly a clean up and refactoring and prepare for next CL. No actual functionality change is expected. It added a new function for the post queueSubmit logic. It moves CommandQueue::queueSubmit() into the same location as queuePresent. Bug: b/267682377 Change-Id: I240934dc4db06ce1277955938427a9e257211277 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/4226006 Commit-Queue: Charlie Lao <cclao@google.com> Reviewed-by: Shahbaz Youssefi <syoussefi@chromium.org> Reviewed-by: Amirali Abdolrashidi <abdolrashidi@google.com>