In the application code, I am reading jcr:created using ValueMap API but when I load content JSON file to the AemContext object I don't see the property(only jcr:created) and getting "null" when I try to read. I am currently using RESOURCERESOLVER_MOCK and I also tried with JCR_MOCK.
When I searched for this issue I have seen a thread but it doesn't really have an answer on how to solve this problem.
This problem is more related to sling-mock of the Apache Sling project than to wcm.io itself, because it affects the ContentLoader from sling-mock. the ContentLoader  has a default list of properties that is ignored when loading content, and "jcr:created" is one of them.