Spawnables in Level Sequence Cause Sequence to Dirty

When a sequence contains a spawnable, it is immediately dirtied after saving and closing

1. Open attached project
2. Open level sequence with cube that has been converted to spawnable
3. See the sequence is dirtied
4. Save
5. See this clears it of being dirty
6. Close out the sequence
7. See the sequence immediately dirties again

Expected: Sequence containing a spawnable does not immediately dirty after saving and closing out of the sequence

Result: Sequence containing a spawnable immediately dirties after saving and closing out of it