Navigation obstacles remain when turning off bCanEverAffectNavigation in Blueprint actor

Editing the bCanEverAffectNavigation flag on an Actor Blueprint is propagating the value of the property to the Blueprint instance, but fails to properly update the navmesh according to the new value. This is a regression from 4.20.3 (CL-4369336).

This was reported and tested in 4.21 (CL-4541578). This was reproduced in Main 4.22 (CL-4614594)

1. Open the UE4 Editor and create a Blank Template project
2. Create an actor blueprint and give it a cube component as the root
3. Add a Navmesh Bounds Volume to the level and place an instance of the blueprint into it
4. Edit the Actor Blueprint (not the instance) to turn off the `bCanEverAffectNavigation` on the cube
5. Move the instance and notice that it leaves behind a hole in the navmesh
6. Manually build paths and notice that the hole remains
7. Delete the instance of the actor. Hole is still there
8. Close the editor and restart. Hole still remains
9. Manually build paths again. The hole is no longer in the navmesh

Results: Phantom obstacles in the navmesh are left behind after disabling 'bCanEverAffectNavigation`

Expected: The navmesh should update properly when the bCanEverAffectNavigation flag is turned off