vkQueueSubmit already performs this operation, so this barrier was
unnecessary.

The only place this is necessary is when the GPU is expected to receive
updates from the CPU post-submit.  ContextVk::synchronizeCpuGpuTime is
the only such use-case in ANGLE.

Bug: angleproject:4897
Change-Id: I7297fbd65d3faabd949dddb6bcaa181053a83193
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2372631Reviewed-by: Charlie Lao <cclao@google.com>
Commit-Queue: Shahbaz Youssefi <syoussefi@chromium.org>