[BUG] the producer metrics of kop topic is not changed when producing

[dockerzhang]

Describe the bug
the producer metrics of kop topic is not changed when producing, still is 0

To Reproduce
Steps to reproduce the behavior:

1. create a partitioned topic
   pulsar-admin persistent create-partitioned-topic t-kop/ns-kop/lookup2 --partitions 30
2. producing message using the created topic
3. show the status of the topic
   bin/pulsar-admin topics partitioned-stats t-kop/ns-kop/lookup2
4. See error

Screenshots