Figure out why serialization of polymorphic lists used to work in Jackson and don't anymore

[metacosm]

Cloning a resource which contains a polymorphic list of items used to work in 2.0.0.Beta5 but doesn't anymore in more recent versions and, this, despite https://stackoverflow.com/questions/34193177/why-does-jackson-polymorphic-serialization-not-work-in-lists#34194367 which seems to indicate that it shouldn't have worked in the first place.

[metacosm]

As indicated in the linked issue, what happened is that JOSDK switched at some point from using its own Jackson mapper, which was actually handling the polymorphic list correctly (because the serialisation configuration was properly set up for it to work), to using Fabric8's own mapper, which is customized with a module that interferes with proper serialisation of polymorphic collections in some situations.

[metacosm]

This should be fixed when we can upgrade to Fabric8 Client 6.6.0.

[metacosm]

This has been fixed in 6.1.0.