[formrecognizer] unskip prebuilt url tests #16535
Description
We are currently skipping all prebuilt model tests that use a URL as input. We have seen an increased incidence of "InvalidimageUrl" errors returned from the service despite sending valid URLs. We see this behavior across languages / regions both with image URLs hosted from github and with blob URLs.
We also need to unskip the changes made in this PR to disable the receipt URL samples: #17036
Service team is notified and looking into it.