MINOR: Enable some AdminClient integration tests

[dengziming]

More detailed description of your change
Enable KRaft in AdminClientWithPoliciesIntegrationTest and PlaintextAdminIntegrationTest
There are some tests not enabled or not as expected yet:

1. testNullConfigs, see KAFKA-13863
2. testDescribeCluster and testMetadataRefresh, currently we don't get the real controller in KRaft mode so the test may not run as expected.

Summary of testing strategy (including rationale)
QA

Committer Checklist (excluded from commit message)

• Verify design and implementation
• Verify test coverage and CI build status
• Verify documentation (including upgrade notes)

[hachikuji]

@dengziming Thanks, just a couple small comments. By the way, let me know if you have any other conversion patches and I can review them.

[showuon]

Thanks for the PR. Left some comments.

[showuon]

Also, the 2 failed tests are introduced by this PR.

Build / JDK 17 and Scala 2.13 / kafka.api.PlaintextAdminIntegrationTest.testDescribeTopicsWithIds(String).quorum=kraft
Build / JDK 17 and Scala 2.13 / kafka.api.PlaintextAdminIntegrationTest.testInvalidIncrementalAlterConfigs(String).quorum=kraft

I checked the topicID issue, it looks like there's a race condition for metadata cache, so that the metadata cache will return ZERO_UUID if empty:
https://github.com/apache/kafka/blob/trunk/core/src/main/scala/kafka/server/metadata/KRaftMetadataCache.scala#L196

Thanks.

[dengziming]

@showuon These 2 tests can be fixed by ensureConsistentKRaftMetadata, I fixed them.

[hachikuji]

Thanks, LGTM!