Align RemoteStorageThreadPool metrics name with KIP-405

In KIP-405, there are 2 metrics defined below:
^{kafka.log.remote:type=RemoteStorageThreadPool, name=RemoteLogReaderTaskQueueSize}
and
^{kafka.log.remote:type=RemoteStorageThreadPool, name=RemoteLogReaderAvgIdlePercent}

However, in Kafka 3.6 release, the actual metrics exposes are:
^{org.apache.kafka.storage.internals.log:name=RemoteLogReaderAvgIdlePercent,type=RemoteStorageThreadPool
org.apache.kafka.storage.internals.log:name=RemoteLogReaderTaskQueueSize,type=RemoteStorageThreadPool}

The problem is the bean domain name is changed from ^{kafka.log.remote} to ^{org.apache.kafka.storage.internals.log}. And the type name is also changed.

We should either update the metrics path in KIP, or fix the path in the code.