Reimporting a static mesh will cause some values to be reset back to defaults

Reimporting a static mesh will cause some Static Mesh Editor values to be reset back to defaults.

This was reported as JIRA UE-22205 back in 4.10 and was marked fix in 4.12. However, I wasn't able to verify it was fixed because reimporting crashes the editor in 4.12.

Licensee Description:

Static Mesh property 'Allow CPUAccess' un-ticks itself when you re-import the mesh.

It's never a problem in-editor if its un-ticked, but in cooked builds this really messes up our stuff.

1. Open a new blank BP project
2. Import the provided .FBX file > Default settings
3. In the Content Browser, double-click the static mesh to open it in the Static Mesh Editor
4. In the Details panel, Enable "Allow CPUAccess" and "Generate Mesh Distance Fields"
5. Save but leave the window open so you can see the values
6. Back in the editor > Content Browser > Right-click the static mesh > Reimport

Results: The 2 values enabled will be reset back to default values when the static mesh is reimported

Expected: For all values to be maintained on reimport