Modified content blueprints are not imported with a space import

Summary

If we have modified/customized blueprints for a space and this space is exported then imported then the newly imported space will not have the modified blueprints which were present in the space.

Environment

Confluence 5.9.4

Steps to Reproduce

1. Go to a test space and click the *** (3 dots) next to the create button
2. The create pop up will appear and at the bottom there will be an option for Add or customise templates for the selected space
3. After clicking this option we can see Blueprint templates which can be edited for this particular space.
4. Edit any one Blueprint.
5. Export the space (xml export)
6. Import the space to a different instance or the same (First delete the existing test space)
7. Again follow the steps 1 and 2 and check the edited Blueprint.

Expected Results

The customized blueprint should be retained

Actual Results

The Blueprint appears to be in the default condition (un-edited)