Make ZkHelixClusterVerifier and its child classes realm-aware

[narendly]

Issues

• My PR addresses the following Helix issues and references them in the PR description:

Fixes #866

Description

• Here are some details about my PR, including screenshots of any UI changes:

Changelist:

1. Make sure constructors accept RealmAwareZkClient
2. Add Builders in each child class of ZkHelixClusterVerifier so that ZkClient configs are configurable and uses realm-aware ZkClient APIs

Tests

• The following tests are written for this issue:

Covered by existing tests

• The following is the result of the "mvn test" command on the appropriate module:

helix-core:

[INFO] Results:
[INFO]
[ERROR] Failures:
[ERROR] TestCleanupExternalView.test:122 external-view for TestDB0 should be removed, but was: ZnRecord=TestDB0, {BUCKET_SIZE=0, IDEAL_STATE_MODE=AUTO, NUM_PARTITIONS=2, REBALANCE_MODE=SEMI_AUTO, REBALANCE_STRATEGY=DEFAULT, REPLICAS=2, STATE_MODEL_DEF_REF=MasterSlave, STATE_MODEL_FACTORY_NAME=DEFAULT}{TestDB0_0={localhost_12918=SLAVE, localhost_12919=MASTER}, TestDB0_1={localhost_12918=MASTER, localhost_12919=SLAVE}}{}, Stat=Stat {_version=5, _creationTime=1583435076996, _modifiedTime=1583435077917, _ephemeralOwner=0} expected: but was:
[ERROR] TestEnableCompression.testEnableCompressionResource:108 expected: but was:
[ERROR] TestRebalanceRunningTask.testFixedTargetTaskAndDisabledRebalanceAndNodeAdded:265 expected: but was:
[ERROR] TestHelixAdminCli.testDeactivateCluster:604 » Helix There are still LEADER in ...
[INFO]
[ERROR] Tests run: 1083, Failures: 4, Errors: 0, Skipped: 1
[INFO]
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 01:11 h
[INFO] Finished at: 2020-03-05T11:11:14-08:00
[INFO] ------------------------------------------------------------------------

mvn test -Dtest=TestCleanupExternalView,TestEnableCompression,TestRebalanceRunningTask,TestHelixAdminCli

[INFO] Tests run: 17, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: 64.876 s - in TestSuite
[INFO]
[INFO] Results:
[INFO]
[INFO] Tests run: 17, Failures: 0, Errors: 0, Skipped: 0
[INFO]
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 02:15 min
[INFO] Finished at: 2020-03-05T15:01:00-08:00
[INFO] ------------------------------------------------------------------------

Commits

• My commits all reference appropriate Apache Helix GitHub issues in their subject lines. In addition, my commits follow the guidelines from "How to write a good git commit message":
  1. Subject is separated from body by a blank line
  2. Subject is limited to 50 characters (not including Jira issue reference)
  3. Subject does not end with a period
  4. Subject uses the imperative mood ("add", not "adding")
  5. Body wraps at 72 characters
  6. Body explains "what" and "why", not "how"

Code Quality

• My diff has been formatted using helix-style.xml
  (helix-style-intellij.xml if IntelliJ IDE is used)

[junkaixue]

Remember to add TODO for Builder refactoring.

[narendly]

This PR is ready to be merged, approved by @dasahcc

Changelist:
Make sure constructors accept RealmAwareZkClient
Add Builders in each child class of ZkHelixClusterVerifier so that ZkClient configs are configurable and uses realm-aware ZkClient APIs