Sample/testing app: enable custom CPU allocation callbacks by default
Sample/testing app: enable custom CPU allocation callbacks by default

Added allocation counting to make sure there are no memory leaks at the end.

GPUOpen-LibrariesAndSDKs/VulkanMemoryAllocator,GPUOpen-LibrariesAndSDKs/VulkanMemoryAllocator,GPUOpen-LibrariesAndSDKs/VulkanMemoryAllocator