[Mutable] Morph Targets can be disabled in packaged builds when Mesh Streaming is enabled

When a Mutable mesh instance is created while the actor spawns at a distance, only the low LODs are generated, and the mesh is created with no Morph Targets registered. Later, when the camera approaches and the higher LODs are streamed in, the Morph Targets are never restored, resulting in incorrect rendering.

1. Open the attached repro project.
2. Play in Editor (PIE).
3. Placed a short distance away is a mesh generated by Mutable from a Mannequin base mesh, with streaming enabled, morphs applied on LOD0/LOD1, and no morphs on LOD2/LOD3.
4. Walk up to the mesh. Confirm that the heartbeat morph is applied.
5. Create a Win64 package.
6. Launch the packaged build and execute steps 4, then check whether the morph is applied.

Result:

The morph is disabled in the packaged build.