Overriding ARM and AAD endpoints for AzureUSGovernment cloud breaks publish

We have built-in ARM and AAD endpoints for AzureCloud, AzureChinaCloud, and AzureUSGovernment. However, specifying them like this should work correcly as well:

However, the above configuration breaks `bicep publish` and causes the following error:

The workaround is to remove the endpoints and just specify the profile like this:
```json
{
"cloud": {
"currentProfile": "AzureUSGovernment",
"credentialPrecedence": [
"AzureCLI"
]
}
}
```

However, this should have worked correctly regardless. Additionally, the bug leads me to believe that this functionality may be broken in AGC.

Start by reproducing `bicep publish` with the AzureUSGovernment profile and explicitly overridden ARM and AAD endpoints, then compare it with the documented workaround that omits those endpoints. Trace how the cloud configuration is consumed during publishing and verify that endpoint overrides work for AzureUSGovernment without regressing the other built-in profiles or AGC.

Written by the indexing model from the issue text.