Material Layers Ignore Virtual Texture Sampler Restrictions

Virtual Textures can be assigned to Texture Sample Parameters that are not configured for Virtual Textures, if that parameter is inside of a Material Layer.

Also found in Release-5.4, CL 32426910

1. Download the attached test project and open
2. Observe the two Material Instances "/Game/MI_Texture_NonVT" and "/Game/MI_Texture_VT". They are Identical besides the former using a Non-Virtual texture ("/Game/T_NonVirtual") and the latter using a Virtual texture ("/Game/T_Virtual").
3. Observe that in the editor viewport, the two spheres both have a texture. Each sphere is assigned the respective material.
4. Observe that the Material Layer "/Game/ML_BasecolorTexture" samples a regular texture, not a virtual texture.
5. Play "Standalone Game". Observe that the sphere with the material ""/Game/MI_Texture_VT" is now black.
6. Observe the lack of any log message or error related to assigning a Virtual Texture to a non-Virtual Texture Sample Parameter.