New-TestResources fails on first few attempts

Most times when I run New-TestResources, I get these errors on the first couple attempts:
```
WARNING: Attempt 1 failed: Exception calling "Invoke" with "0" argument(s): "The running command stopped because the preference variable "ErrorActionPreference" or common parameter is set to Stop: Your Azure credentials have not been set up or have expired, please run Connect-AzAccount to set up your Azure credentials.". Trying again in 10 seconds...
WARNING: Attempt 2 failed: Exception calling "Invoke" with "0" argument(s): "The running command stopped because the preference variable "ErrorActionPreference" or common parameter is set to Stop: The identity of the calling application could not be established.". Trying again in 20 seconds...
```

It usually ends up succeeding, but it seems that we should be able to avoid hitting these errors initially.

Start at the New-TestResources entry point and reproduce the first-attempt failures, noting the retry and authentication messages. Trace the setup and authentication path responsible for those attempts; done means the command succeeds without the initial credential or identity errors during normal runs.

Written by the indexing model from the issue text.