[Modules] Update App config tests

[eriqua]

Description

Adding a specific test for private endpoints. Using them with public network access disabled does not allow to create/access keyValues child resource from the GH runner.
Tested idempotency by deploying the module twice, skipping removal the first time.
Also updated condition to disable public network access if pe are set. Not needed for this resource since it's done by the service automatically.

Pipeline references

For module/pipeline changes, please create and attach the status badge of your successful run.

Pipeline

Type of Change

Please delete options that are not relevant.

• Bugfix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Update to documentation

Checklist

• I'm sure there are no other open Pull Requests for the same update/change
• My corresponding pipelines / checks run clean and green without any errors or warnings
• My code follows the style guidelines of this project
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation (readme)
• I did format my code