Static lighting isn't bouncing when using Layered Materials

Static lighting will not bounce on the ceiling when using a Layered Material. The Material Attributes Layers node is used which doesn't appear in 4.24.3 so this isn't a regression.

This was reported and tested in 4.25.3 (CL-13942748) and reproduced in Main 4.26 (CL-14049719)

1. Open the UE4 Editor and create a Blank Project
2. Create a Layered MAterial
3. Create a closed environment/room that is not affected by sky/directional lights.
4. Place a static point light close to the ceiling and assign layered materials to every mesh

Results: Layered materials prevent static lights from bouncing and will make some meshes appear black.

Expected: Bounced static lighting expected, and is achieved by replacing layered materials with non-layered ones.