Use either `Add existing elements` tools on an empty Action Flow view removes the background image even if nothing has been imported

[gcoutable]

Steps to reproduce

1. Create a SysMLV2 model
2. Add at least one PartUsage in the model
3. Create an Action Flow view on the Package
4. Use the tool Add existing elements

Expected behavior

Since nothing should be imported in the diagram, the background image should still be displayed

Actual behavior

Nothing is imported, but the background image is not displayed anymore