[Portal] Change auth token retrieval for non ARM endpoints in portal extension

### Severity

P2 - High (Major functionality broken)

### Describe the Bug with repro steps

Portal currently logs errors for accessing non arm endpoints like powerapps.com using arm tokens.
The work here requires to get auth token for these endpoints separately by contacting the service to access them. This will be blocked soon by portal and with current whitelisting it might not work.

### What type of Logic App Is this happening in?

Consumption (Portal)

### Are you experiencing a regression?

_No response_

### Which operating system are you using?

Windows

### Did you refer to the TSG before filing this issue? https://aka.ms/lauxtsg

Yes

### Workflow JSON

```json

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### Screenshots or Videos

_No response_

### Environment

All

### Additional context

_No response_

No file or test paths are named. Start by locating the portal extension's auth-token retrieval entry point and reproduce the error against a non-ARM endpoint such as powerapps.com. Done means those endpoints obtain a service-specific token and no longer produce errors from using an ARM token.

Written by the indexing model from the issue text.