[0.3.2] Error when saving the extension configuration for mobile - edge network domain expected

**Issue description**
When trying to save an error is reported, requiring to provide the edge network domain.
The edge network domain field is empty, not even showing the expected default value: edge.adobedc.net.


Expected resolution
- Or the edge domain field to be initialized with the default value.
- Or the enablement documentation to describe the domain value to insert.

Issue in ./help/tutorial-comprehensive-technical-v22/modules/module0/ex3.md

Review ./help/tutorial-comprehensive-technical-v22/modules/module0/ex3.md and the mobile extension configuration steps. Check whether the edge domain is initialized or documented there, then verify that the chosen resolution addresses the reported save error and clearly tells users which value to enter.

Written by the indexing model from the issue text.