Update schemas used in policy engine functional tests

[zburstein]

The functional tests for policy-engine use schemas defined within the tests to verify the responses are accurate. These tests should instead use the classes that are used to build the responses to verify the schemas. The intent here is to ensure that the response complies with the contract defined in the API spec. A dev can change the schema in the tests to pass, but this can end up being a bad test because it may fail to catch potential issues that would be casued downstream if another service is using the defined api contract.