Tree building sorts children by name so we must name our storages.

See build_smartproxy_affinity_node:
https://github.com/ManageIQ/manageiq/blob/e405e1ad52072a0c7f341481d6457841e849450e/vmdb/app/controllers/ops_controller/settings/common.rb#L1272

This fixes a sporadic test failure where the storages are in unexpected order because they have no name.