layers: Force all device extensions disabled initially
layers: Force all device extensions disabled initially

Should really fix device initialization so we don't need to do this
explicitly.

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