Currently count includes keys from different resource(s) if the keys
are a prefix of the specified resource/key.
Consider the following keys:
A: <storage-prefix>//foo.bar.io/machines
B: <storage-prefix>//foo.bar.io/machinesets
If we ask for the count of key A, the result will also include the
keys from key B since key B shares the same prefix as key A.
Append a separator to mark the end of the key, this will exclude all
other keys from a different resource that is a prefix of the specified
key.
Kubernetes-commit: 7e445867aa4d37a67591faf6e5508abaea69d216
bd49a32a3f