dbus binding doesn't detect values with incorrect types in arrays, it elides them

For example, the following uses an incorrect a(sss), but the call gets through... 
```
busctl --user call org.storage.stratis1 /org/storage/stratis1/1 org.storage.stratis1.pool CreateFilesystems a(sss) 3 volume1 /dev/mount/point 10 volume2 /dev/mount/point2 11 volume3 /dev/mount/point3 12
a(oqs)qs 00 "Ok"
```

It doesn't seem to be a big deal - the filesystems array is 0 length.
