Keys applied in Sequencer to Exponential Height Fog's Fog Density (Second Fog Data) are applied to primary fog density

Sequencer keys applied to an Exponential Height Fog actor's Second Fog Data | Fog Density are applied to the fog actor's primary Fog Density instead. Second Fog Data was introduced in 4.22.

This was reported and tested in 4.22.2 (CL-6574378) and reproduced in Main 4.23 (CL-6662737).

1. Open the UE4 Editor and create a Blank project
2. Add an exponential height fog actor to the Level
3. Create a level sequence
4. Add the Exponential Height Fog actor to the Sequence
5. Add the HeightFogComponent and Fog Density (Second Fog Data) tracks
6. Set a pair of keys on Fog Density (Second Fog Data) to interpolate their values
7. Scrub the sequence

Results: Values keyed in Second Fog Data | Fog Density will be applied to the primary fog density instead.

Expected: These values should be separately keyable in Sequencer