Expose to Matinee requires variable to be "editable" for it is usable in Sequencer/Matinee

Expose to Matinee requires variable to be "editable" as well.

If this is expected, can we have "Editable" be enabled when you enable "Expose to Matinee"?

1. Create a Blueprint actor and add a variable to it (Named TestVar)
2. In the variable details, enable "Expose on Matinee"
3. Place an instance of the BP in the level
4. Create a level sequence
5. Add a track for the BP actor
6. Try to add a variable track for the BP

Result: No track available
Expected: Can see TestVar in the +Track menu

7. Go back to the variable details and enable "Editable"
8. Try to add a variable track in sequencer again

Result: TestVar appears

Blueprint variables should not be required to be public in order to be visible in Sequencer