Fixup kubelet handlePodInfo to be namespace aware

Closes #1688 
This is not a well defined ordering. Imagine the pods with (ns, name): ("a", "b") and ("b", "a").

Must be:

```
if s[i].Namespace != s[j].Namespace {
  return s[i].ID < s[j].ID
}
return s[i].Namespace < s[j].Namespace
```