VirtualTextureStreamingPriority cannot be set per TextureLODGroup

It is currently not possible to set a VirtualTextureStreamingPriority via the TextureLodGroups that are defined in a device profile.

Steps to Reproduce

• Create a new project or open an existing one
• Modify any DeviceProfiles.ini (Base, Default, Windows, etc...)
• In the TextureLODGroups array, add a group with a VirtualTextureStreamingPriority

TextureLODGroups=(Group=TEXTUREGROUP_World,MinLODSize=1,MaxLODSize=16384,LODBias=0,MinMagFilter=aniso,MipFilter=point,MipGenSettings=TMGS_SimpleAverage,VirtualTextureStreamingPriority=AboveNormal)
+TextureLODGroups=(Group=TEXTUREGROUP_WorldNormalMap,MinLODSize=1,MaxLODSize=16384,LODBias=0,MinMagFilter=aniso,MipFilter=point,MipGenSettings=TMGS_SimpleAverage,VirtualTextureStreamingPriority=AboveNormal)

• Launch the Engine
• Notice that any texture related to this group will not have the correct VirtualTextureStreamingPriority