Use java.lang.ref.Cleaner in controller.cluster.io
Improve temporary file clean up by using a Cleaner to dispatch
cleaning tasks. Since it gives us a Cleanable, we can dispense with
a tracking map and removal from it -- Cleanable makes sure it is
called exactly once.
JIRA: CONTROLLER-1911
Change-Id: I5fb715102912359cf002129d25a7433199826982
Signed-off-by: tadei.bilan <tadei.bilan@pantheon.tech>
Signed-off-by: Robert Varga <robert.varga@pantheon.tech>
(cherry picked from commit
e0e956ecf0a4e5085f33e67f4fb73141876f1668)