(PUP-11752) fqdn_rand_string_spec.rb relies on legacy fqdn fact

There could potentially be other modules that are impacted too

Author: AriaXLi

Diff for: spec/functions/fqdn_rand_string_spec.rb

@@ -57,7 +57,7 @@ def fqdn_rand_string(max, args = {})
 
     # workaround not being able to use let(:facts) because some tests need
     # multiple different hostnames in one context
-    allow(scope).to receive(:lookupvar).with('::fqdn', {}).and_return(host)
+    allow(scope).to receive(:lookupvar).with('facts', {}).and_return({ 'networking' => { 'fqdn' => host } })
 
     function_args = [max]
     if args.key?(:charset) || !extra.empty?