A change in Vulkan-Headers changes the value of VK_NULL_HANDLE, exposing
an invalid usage in ANGLE, which is fixed in this change.

Bug: angleproject:5879
Change-Id: I136fdc9e707650a060eaee062c7cf8cf24d9e8b2
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2831998Reviewed-by: Tim Van Patten <timvp@google.com>
Commit-Queue: Shahbaz Youssefi <syoussefi@chromium.org>