Configure Hazelcast to have 1 backup to reduce memory

Configure Hazelcast to have 1 backup to reduce memory

Currently Hazelcast is configured to have 3 synchronous backups
and 3 asynchronous backups. These are separate, meaning there will
be 7 copies in the cluster (1 original + 3 sync + 3 async backups).
Even if only 1 instance of CPS/NCMP is running, it will have 7 copies
in memory.

Given that CPS/NCMP is typically only deployed using 1 or 2 instances,
the settings are changed to 1 synchronous backup (same as Hazelcast's
default configuration). This change has been tested and shown to reduce
heap usage by around 100MB during 20K CM-handle registration.

Issue-ID: CPS-2146
Signed-off-by: danielhanrahan <daniel.hanrahan@est.tech>
Change-Id: I4a5f6d83bc35e2c13cfb32002e38dc365da34c8e