Vulkan: Invalidate depth/stencil unconditionally * Moved depth/stencil content invalidation during swapImpl() to doDeferredAcquireNextImage(), so it can be done regardless of whether render pass optimization is done. Bug: angleproject:6861 Change-Id: I47fab18afe5b178bf55c2df3df712c40118aff1f Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/3370583 Reviewed-by: Shahbaz Youssefi <syoussefi@chromium.org> Reviewed-by: Jamie Madill <jmadill@chromium.org> Commit-Queue: Amirali Abdolrashidi <abdolrashidi@google.com>