Tests failing due to DBCP integration

This ticket has been filed for discussion over tests failing due to Narayana-DBCP integration being developed in the PR https://github.com/kiegroup/jbpm/pull/1217. The stacktrace is in the attachment.

Please note that these tests fail only with H2 database. Production databases does not show this error.

The list of failing tests:
org.jbpm.bpmn2.IntermediateEventTest.testIntermediateCatchEventConditionFilterByProcessInstance
org.jbpm.bpmn2.IntermediateEventTest.testConditionalProcessFactInsertedBefore
org.jbpm.memory.MemoryLeakTest.findEventSupportRegisteredInstancesTest
org.jbpm.bpmn2.IntermediateEventTest.testIntermediateCatchEventTimerDurationWithError
org.jbpm.persistence.session.PersistentStatefulSessionTest.testSetFocus
org.jbpm.persistence.session.PersistentStatefulSessionTest.testLocalTransactionPerStatement