add info to help clarify success after warnings

[bmc-msft]

During a deployment this morning, AAD failed the first attempt to create an application password and upon retry succeeded.

The error message given by AAD was scary:

WARNING:root:unable to create app password: request did not succeed: HTTP 403 - {
  "error": {
    "code": "Authorization_RequestDenied",
    "message": "Insufficient privileges to complete the operation.",
    "innerError": {
      "date": "2021-03-03T15:39:35",
      "request-id": "GUID",
      "client-request-id": "GUID"
    }
  }
}

This error gave me the impression that the AAD password creation failed, yet the deployment continued.

This PR adds a comment in the success case to clarify when the password creation succeeded.

Now, the above case will look like this:

WARNING:root:unable to create app password: request did not succeed: ...
INFO:root:app password created