How to Include user session related configuration in my extension?

I added my thingshape in the UserManagementSubsystem to put variables in session. But when I try to export my changes using my model tag and then try to import it on some other machine I dont get the thingshape added in the UserManagementSubsystem. What I need to do to include this configuration change in my extension as well?

I tried adding my app's model tag to UserManagementSubsystem as well and exported it. But I got error while importing that system objects. Apparently we cant import system objects.