tests: Add positive check for deleted DSLayouts
tests: Add positive check for deleted DSLayouts

Deleting DescriptorSetLayouts before associated DescriptorSets
previously caused crashes.

Change-Id: I21fda3826e5836d4885e6baa8807937223117fd3

KhronosGroup/Vulkan-LoaderAndValidationLayers,KhronosGroup/Vulkan-LoaderAndValidationLayers,KhronosGroup/Vulkan-LoaderAndValidationLayers,KhronosGroup/Vulkan-LoaderAndValidationLayers