Sequencer doesn't save mobility for component children

When the transform is actuated for a static component only its pre animated state is saved, but its mobility will be set to movable. This causes its children to become movable as well. When the component's children are not animated themselves, there is no pre animated state to restore, so they remain movable. If they are animated, their pre animated state is saved after they have been made movable, so it will be restored to the incorrect value.

1. Add a static mesh cube actor to a level
2. Add a child static mesh sphere component to the cube
3. Set both component's mobilities to static
4. Create a new sequence and add the cube actor to it
5. Add a transform track for the cube if none exists
6. With the sequence open verify both the cube and sphere's mobility have changed
7. Close the sequence

RESULT

The cube's mobility will change back to static, but the sphere will remain movable. If you add a transform track for the sphere it's mobility will still remain movable after the sequence is closed too.