FBX Scene imports with an addition Scene Root in the Hierarchy

There seems to be a second Scene root being created when importing an fbx scene. Something of note is that in the scene import dialogue we only see one "RootNode" listed.

This has been found to occur as far back as binary 4.23.1 CL 9631420 so far but testing shows this didn't always function this way. This seems to be a regression, but not sure what the range on this could be yet. Leaving as unconfirmed for now.

1. Download the [Link Removed] scene from the drive
2. Open QAGame
3. Open TM-ImportScene
4. File > Import Into Level
5. Select ImportScene_01.fbx and Open
6. Select a Folder to import to and click OK
7. Select Import
8. Refer to the FBX scene hierarchy in the FbxScene_ImportScene_01 asset editor

Results: There will be two DefaultSceneRoots, one parented to the other.

Expected: There will be one DefaultSceneRoot parented to the FbxScene and everything imported will be a child under it.