Messages not distributed across Kafka partitions

Change AlarmStateTransitionNotification Kafka message key to be
the message count instead of a constant to get a good
distribution across Kafka partitions

JAH-926 event and AlarmStateTransition messages are not
distributed across Kafka partitions

Change-Id: I0291168635f2311585de011d9003f6af06120b86
Merge "Messages not distributed across Kafka partitions"