When importing a course with grid images specified, the images are not imported into the target course.

To reproduce:
1) Create course and set to Grid format.
2) Add images to grid format
3) Create new empty stub target course.
4) Import the Source course into Target course
5) Grid icons missing.

What we expected:
Grid Images would be imported with the rest of the content

What actually happened:
Grid images were not imported with the rest of the content.

Of note, a manual backup -> download -> upload -> restore to new course does not appear to be affected.