[OWL-1695] Add test of consumeHeartbeatQueue(). Rename a non-logical variable name.
[OWL-1695] Add test of consumeHeartbeatQueue().
Rename a non-logical variable name.

Cepave/open-falcon-backend,Cepave/open-falcon-backend,Cepave/open-falcon-backend,Cepave/open-falcon-backend,masato25/open-falcon-backend,Cepave/open-falcon-backend,masato25/open-falcon-backend,masato25/open-falcon-backend,masato25/open-falcon-backend,masato25/open-falcon-backend,Cepave/open-falcon-backend,masato25/open-falcon-backend