BPMN processes don't work when CanonicalKieModule is used

When using executable model in a kjar that contains BPMN process definitions in the form of bpmn files, the processes don't work.

To reproduce the problem, run RuleFlowIntegrationTest [1], with executable model enabled in the ruleflow-group kjar.

[1] https://github.com/kiegroup/droolsjbpm-integration/blob/78cb770577679cb46b1f5bbf3e38124499d3cba6/kie-server-parent/kie-server-tests/kie-server-integ-tests-drools/src/test/java/org/kie/server/integrationtests/drools/RuleFlowIntegrationTest.java#L35