Update the product serializer

Before LTSS, the product serializer returned true for the free field of
any product

That is no longer true in the Public Cloud scenario, where LTSS is not free

This Fixes that case

app/serializers/v3/product_serializer.rb

@@ -33,8 +33,11 @@ def eula_url
   end
 
   def free
-    # Everything is free on RMT :-)
+    # Everything is free on RMT :-) outside of the Public Cloud (i.e. LTSS)
     # Otherwise Yast and SUSEConnect will request a regcode when activating an extension
+    # FIXME
+    return object.free if defined?(SccProxy::Engine) && object.extension?
+
     true
   end
 

engines/instance_verification/spec/requests/api/connect/v3/systems/products_controller_spec.rb

@@ -540,6 +540,7 @@
           context 'when no regcode is provided' do
             it 'activates the product' do
               data = JSON.parse(response.body)
+              expect(data['product']['free']).to eq(false)
               expect(data['id']).to eq(product.id)
             end
           end