Storage naming caused the sort_by to sort storage_9 after storage_10.

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 an unexpected order because the sequencing created storages with names that didn't always sort in the same order as their creation order.

Before:

```
["storage_2", "storage_1", "storage_10", "storage_9"].sort
=> ["storage_1", "storage_10", "storage_2", "storage_9"]
```

After:
```
["storage0000000000002", "storage0000000000001", "storage0000000000010", "storage0000000000009"].sort
=> ["storage0000000000001", "storage0000000000002", "storage0000000000009", "storage0000000000010"]
```