preset Topology
Optional. The topology implemented in this hub. Currently, this field is only used when policyMode = PRESET. The available preset topologies are MESH and STAR. If presetTopology is unspecified and policyMode = PRESET, the presetTopology defaults to MESH. When policyMode = CUSTOM, the presetTopology is set to PRESET_TOPOLOGY_UNSPECIFIED. Possible values are: MESH
, STAR
.