Title: Execute operations

Describe the issue:
Sample is compatible 6.0 but not 6.1

Suggestions for improvement:

URL address = new URL(url + "/runtime/" + deploymentId + "/execute");
must be
URL address = new URL(url + "/execute");

Additional information:

In addition in 6.1 if you want to use POJO as variable for exemple to use SetProcessInstanceVariablesCommand or StartProcessCommand, you need to add the header "Kie-Deployment-Id" (org.kie.services.client.serialization.JaxbSerializationProvider.EXECUTE_DEPLOYMENT_ID_HEADER) with as value the deployment id