[Landscape] Collision Object Type Requires WorldStatic to Paint Foliage

No longer able to paint foliage when new Collision Object Type is applied to the landscape.

Reproduced in 4.17.2 CL 3658906, 4.18.3 CL 3832480, and 4.19 P5 3898826

1. Create a new blank project, no starter content
2. Create new level
3. Create a new landscape in level
4. Go to Project Settings > Collision > Object Settings and create new Object Channel
5. Select Landscape and go to Collision Options in the Details panel
6. In the Collision Settings > Collision Presets select Custom. In the Object Type dropdown, select the previously created Object Channel
7. Add meshes to foliage painter, attempt to paint foliage onto the landscape

Result: Brush gizmo for painting foliage does not appear
Expected: Foliage should paint on landscape despite the collision object type