Fixed issues in Cruise Control

Review the list of Cruise Control issues that are resolved in Cloudera Runtime 7.1.7.

CDPD-22635: Some Kafka metrics are collected incorrectly in Cruise Control

The issue regarding metric collection has been resolved, and the network inbound/outbound capacity goals can be used without any error.

CDPD-23610: Failure in topic configuration endpoint

The topic_configuration does not fail with NullPointerException when the broker rack id is not configured.