HOTFIX: build error caused by DescribeClientQuotasRequest

[chia7712]

related to #8083

fix the build error and add some tests.

Committer Checklist (excluded from commit message)

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

[chia7712]

@bdbyrne @cmccabe FYI

[chia7712]

the following error happens on scala 2.13

22:15:32 /home/jenkins/jenkins-slave/workspace/kafka-pr-jdk11-scala2.13/core/src/main/scala/kafka/server/KafkaApis.scala:2825: overloaded method constructor DescribeClientQuotasResponse with alternatives:
22:15:32   (x$1: org.apache.kafka.common.protocol.types.Struct,x$2: Short)org.apache.kafka.common.requests.DescribeClientQuotasResponse <and>
22:15:32   (x$1: Int,x$2: Throwable)org.apache.kafka.common.requests.DescribeClientQuotasResponse <and>
22:15:32   (x$1: java.util.Map[org.apache.kafka.common.quota.ClientQuotaEntity,java.util.Map[String,Double]],x$2: Int)org.apache.kafka.common.requests.DescribeClientQuotasResponse
22:15:32  cannot be applied to (Iterable[(org.apache.kafka.common.quota.ClientQuotaEntity, Iterable[(String, Double)])], Int)
22:15:32         new DescribeClientQuotasResponse(result, requestThrottleMs))

the root cause is that the return type of mapValues is changed from Map to MapView on scala 2.13. Hence, the type of "toJava" is changed from Map to Iterable as well.

[bdbyrne]

LGTM, thanks for the quick fix. @cmccabe can you merge please?

[bdbyrne]

Just saw the compile fix too. Thank you.

[bdbyrne]

I'll fix the kafka.server.RequestQuotaTest

[chia7712]

the flaky is traced by #8302

[mimaison]

retest this please

[cmccabe]

LGTM. I'll merge this to unblock Jenkins.