demos: Add functionality on Linux for single GPU
demos: Add functionality on Linux for single GPU

Vulkaninfo JSON output appears as expected in Linux environment.
Implemented on a system with a single GPU.

Change-Id: I3179b3d479270c71a9f7955b41d19924baf10bfb

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