Setting the policy lets you list the URL patterns that specify which web apps can't ask users to grant them access to file types.
Leaving the policy unset means DefaultFileHandlingGuardSetting applies for all web apps, if it's set. If not, the user's personal setting applies.
For URL patterns which match neither FileHandlingAllowedForUrls nor FileHandlingBlockedForUrls, DefaultFileHandlingGuardSetting, or the users' personal settings, will be used, in that order.
URL patterns must not conflict with FileHandlingAllowedForUrls. Neither policy takes precedence if a URL matches with both.
For detailed information on valid url patterns, please see https://cloud.google.com/docs/chrome-enterprise/policies/url-patterns. * is not an accepted value for this policy.