Fix connectivity-unit-test-harness.jar to work with jackson-databind 2.13.1.

Customers who have created their own connectivity plug-in codec using the UnitTestHarness.java sample should remove any references to UntypedObjectDeserializer.Vanilla from that class and instead subclass the base class UntypedObjectDeserializer if needed. This is required due to some breaking changes in jackson-databind v2.13.1.