Similarly to common test init, these specific tests init the Vulkan
resources with validation layers when they might not be available.
Fix this by checking for the appropriate define.

Bug: b/168744561
Change-Id: I93dd3bac839297ced07cb2c4cbbcf64db2e65a1f
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2419041Reviewed-by: Jamie Madill <jmadill@chromium.org>
Commit-Queue: Jamie Madill <jmadill@chromium.org>