Opening a new sequence can have SavePreAnimatedState and RestorePreAnimatedState called out of order

When switching to a sequence where the current time is not in the target view range the PreAnimatedState of the new sequence will be saved before restoring the PreAnimatedState of the old sequence. 

1. Create two sequences with a cube animated with a transform track and two keys
2. Scroll one so the start and end frame are not visible in the timeline
3. Put a breakpoint in FMovieScenePreAnimatedState::RestorePreAnimatedStateImpl
4. Put a breakpoint in FMovieScenePreAnimatedState::SavePreAnimatedState
5. With one sequence open, open the other.

RESULT

When switching to the sequence where it's start and end frame are off screen SavePreAnimatedState will be called before RestorePreAnimtedStateImpl. When switching to the other they will be called in the opposite (and correct)  order.