The originally-imported BPMN had valid process logic but no
<bpmndi:BPMNDiagram> section with shape/edge coordinates. bpmn-js needs
the BPMNDI to lay out the diagram visually. Added linear left-to-right
layout: 11 BPMNShape (1 start + 9 serviceTasks + 1 end) + 10 BPMNEdge.
Process logic XML unchanged.