`VK_INSTANCE_LAYERS` log messages don't interact when with `vk_loader_settings.json` `layers` section

[christophe-lunarg]

VK_INSTANCE_LAYERS allows enabling and ordering the layers, including implicit and explicit layers.

This is working fine when the layers section of vk_loader_settings.json is not written.

If layers is written but remains empty, VK_INSTANCE_LAYERS is ignored and not layers are executed as expected.

However, the Vulkan Loader log messages when enabling only LAYERS messages are a bit confusing (VK_INSTANCE_LAYERS is correctly ignored but the warnings says the layers are added):

Launching Vulkan Application:
- Executable: E:\VulkanSDK\1.4.335.0-rc\Bin\vkcube.exe
- Working Directory: E:\VulkanSDK\1.4.335.0-beta1\Bin
- Command-line Arguments:
  - --suppress_popups
- Environment Variables:
  - VK_INSTANCE_LAYERS=VK_LAYER_KHRONOS_profiles;VK_LAYER_KHRONOS_validation;VK_LAYER_NV_optimus
- Log file: C:\Users\Piranha\VulkanSDK\vkcube.txt

Selected WSI platform: win32

[Vulkan Loader] WARNING | LAYER: env var 'VK_INSTANCE_LAYERS' defined and adding layers: VK_LAYER_KHRONOS_profiles;VK_LAYER_KHRONOS_validation;VK_LAYER_NV_optimus

[Vulkan Loader] WARNING | LAYER: env var 'VK_INSTANCE_LAYERS' defined and adding layers: VK_LAYER_KHRONOS_profiles;VK_LAYER_KHRONOS_validation;VK_LAYER_NV_optimus
[Vulkan Loader] LAYER:          vkCreateInstance layer callstack setup to:
[Vulkan Loader] LAYER:             <Application>
[Vulkan Loader] LAYER:               ||
[Vulkan Loader] LAYER:             <Loader>
[Vulkan Loader] LAYER:               ||
[Vulkan Loader] LAYER:             <Drivers>

Selected GPU 0: NVIDIA GeForce RTX 3080 Ti, type: DiscreteGpu
[Vulkan Loader] DRIVER:         vkCreateDevice layer callstack setup to:
[Vulkan Loader] DRIVER:            <Application>
[Vulkan Loader] DRIVER:              ||
[Vulkan Loader] DRIVER:            <Loader>
[Vulkan Loader] DRIVER:              ||
[Vulkan Loader] DRIVER:            <Device>
[Vulkan Loader] DRIVER:                Using "NVIDIA GeForce RTX 3080 Ti" with driver: "C:\WINDOWS\System32\DriverStore\FileRepository\nv_dispi.inf_amd64_20ae8f14a487d5db\nvoglv64.dll"