[BUG]: Configuration saved from calibrate operator should be read-only with sampled stats (regression)

[pascaleproulx]

Describe the bug
After saving the calibrated configuration, in the config operator the config shows '0s' instead of a read-only config with a mean and std deviation values. This looks like a regression since I think we had that at some point: #4377

To Reproduce
Steps to reproduce the behavior:

1. Calibrate a model with data
2. Save for reuse
3. Open the configure operator for that same model and look for the new config called "Calibrated: ..."

Screenshots

Additional context
Add any other context about the problem here.