CSAT for uploading reports is optional. If it's present, reporting user ID can be retrieved from it.
It's also used for Blob service requests (report upload). If it's not present, a service-to-service token is retrieved.
This diff handles the case, when requesting UserIdentity (CSAT) is present, but Identity verification failed.
In this case, we need service-to-service token, the same as for non-existing credential.
Depends on D12416