Vulkan: remove unnecessary transition of external images Since semaphore has been supported, the code for changing external texture layout and queue family is not necessary anymore. So remove them. Bug: angleproject:3289 Change-Id: I5470fa4bf7db7ee4c68f157674cf907a8e455d75 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/1964655 Commit-Queue: Michael Spang <spang@chromium.org> Reviewed-by: Shahbaz Youssefi <syoussefi@chromium.org> Reviewed-by: Michael Spang <spang@chromium.org>