Azure: updating FILE_SERVICE_HOST variable
File service is currently failing integration tests because FILE_SERVICE_HOST is being set as https://${AZURE_DNS_NAME}/api/file/v2//getFileList (the variable is not getting substituted, see https://community.opengroup.org/osdu/platform/system/file/-/jobs/106257#L1719). This change should make the value for the FILE_SERVICE_HOST variable correct.