…afkaMetricsContext (#8811)

Also added a new unit test to verify the functionality and expectations.

Author: Randall Hauch <[email protected]>
Reviewer: Konstantine Karantasis <[email protected]>

* 'trunk' of github.com:apache/kafka: (46 commits)
  MINOR: improve code encapsulation between StreamThread and TaskManager (apache#8819)
  Fixing KAFKA-10094 (apache#8797)
  KAFKA-9851: Revoking Connect tasks due to connectivity issues should also clear the running assignment (apache#8804)
  KAFKA-9840; Skip End Offset validation when the leader epoch is not reliable (apache#8486)
  HOT_FIX: Update javadoc since imports added (apache#8817)
  KAFKA-8011: Fix flaky RegexSourceIntegrationTest (apache#8799)
  KAFKA-9570: Define SSL configs in all worker config classes, not just distributed (apache#8135)
  KAFKA-10111: Make SinkTaskContext.errantRecordReporter() a default method (apache#8814)
  KAFKA-10110: Corrected potential NPE when null label value added to KafkaMetricsContext (apache#8811)
  MINOR: Change the order that Connect calls `config()` and `validate()` to avoid validating if the required ConfigDef is null (apache#8810)
  MINOR: fix backwards incompatibility in JmxReporter introduced by KIP-606
  MINOR: Fix javadoc warnings (apache#8809)
  KAFKA-9441: Improve Kafka Streams task management (apache#8776)
  fix the broken links of streams javadoc (apache#8789)
  KAFKA-10040; Make computing the PreferredReplicaImbalanceCount metric more efficient (apache#8724)
  KAFKA-10066: TestOutputTopic should pass record headers into deserializers (apache#8759)
  MINOR: Add explanation for disabling forwarding from value transformers (apache#8771)
  KAFKA-10033: Throw UnknownTopicOrPartitionException if altering configs of non-existing topic
  KAFKA-9434: automated protocol for alterReplicaLogDirs (apache#8311)
  KAFKA-9313: Set `use_all_dns_ips` as the new default for `client.dns.lookup` (KIP-602) (apache#8644)
  ...

Conflicts:
* build.gradle: take upstream changes regarding heap memory
configuration for the build.

* apache-github/trunk: (33 commits)
  MINOR: fix HTML markup (apache#8823)
  KAFKA-10012; Reduce overhead of strings in SelectorMetrics (apache#8684)
KAFKA-9216: Enforce internal config topic settings for Connect workers
during startup (apache#8270)
  KAFKA-10097: Internalize checkpoint data (apache#8820)
KAFKA-10033: Throw UnknownTopicOrPartitionException when modifying a
non-existent topic's config
MINOR: improve code encapsulation between StreamThread and TaskManager
(apache#8819)
  Fixing KAFKA-10094 (apache#8797)
KAFKA-9851: Revoking Connect tasks due to connectivity issues should
also clear the running assignment (apache#8804)
KAFKA-9840; Skip End Offset validation when the leader epoch is not
reliable (apache#8486)
  HOT_FIX: Update javadoc since imports added (apache#8817)
  KAFKA-8011: Fix flaky RegexSourceIntegrationTest (apache#8799)
KAFKA-9570: Define SSL configs in all worker config classes, not just
distributed (apache#8135)
KAFKA-10111: Make SinkTaskContext.errantRecordReporter() a default
method (apache#8814)
KAFKA-10110: Corrected potential NPE when null label value added to
KafkaMetricsContext (apache#8811)
MINOR: Change the order that Connect calls `config()` and `validate()`
to avoid validating if the required ConfigDef is null (apache#8810)
MINOR: fix backwards incompatibility in JmxReporter introduced by
KIP-606
  MINOR: Fix javadoc warnings (apache#8809)
  KAFKA-9441: Improve Kafka Streams task management (apache#8776)
  fix the broken links of streams javadoc (apache#8789)
KAFKA-10040; Make computing the PreferredReplicaImbalanceCount metric
more efficient (apache#8724)
  ...