Trouble exporting kafka metrics via JMX

[saadgit]

Similar to #739

I am not able to get kafka.server metrics over JMX. jConsole doesnt show kafka.server running but in broker logs, kafka.server is started. On curl localhost:9999/metrics inside broker gives empty reply.
Below is the docker-compose from cp-all-in-one (5.2.1) with some additional properties for KAFKA_JMX_HOST, KAFKA_JMX_PORT, and KAFKA_JMX_OPTS

version: '2'
services:
  zookeeper:
    image: confluentinc/cp-zookeeper:5.2.1
    hostname: zookeeper
    container_name: zookeeper
    ports:
      - "2181:2181"
    environment:
      ZOOKEEPER_CLIENT_PORT: 2181
      ZOOKEEPER_TICK_TIME: 2000
      
  broker:
    image: confluentinc/cp-enterprise-kafka:5.2.1
    hostname: broker
    container_name: broker
    depends_on:
      - zookeeper
    ports:
      - "29092:29092"
      - "9092:9092"
    environment:
      KAFKA_BROKER_ID: 1
      KAFKA_ZOOKEEPER_CONNECT: 'zookeeper:2181'
      KAFKA_LISTENER_SECURITY_PROTOCOL_MAP: PLAINTEXT:PLAINTEXT,PLAINTEXT_HOST:PLAINTEXT
      KAFKA_ADVERTISED_LISTENERS: PLAINTEXT://broker:29092,PLAINTEXT_HOST://localhost:9092
      KAFKA_METRIC_REPORTERS: io.confluent.metrics.reporter.ConfluentMetricsReporter
      KAFKA_OFFSETS_TOPIC_REPLICATION_FACTOR: 1
      KAFKA_GROUP_INITIAL_REBALANCE_DELAY_MS: 0
      KAFKA_JMX_HOSTNAME: localhost 
      KAFKA_JMX_PORT: 9999
      KAFKA_JMX_OPTS: "-Dcom.sun.management.jmxremote -Dcom.sun.management.jmxremote.authenticate=false -Dcom.sun.management.jmxremote.ssl=false -Djava.rmi.server.hostname=localhost -Dcom.sun.management.jmxremote.local.only=false -Dcom.sun.management.jmxremote.rmi.port=9999 -Dcom.sun.management.jmxremote.port=9999 -Djava.net.preferIPv4Stack=true"
      CONFLUENT_METRICS_REPORTER_BOOTSTRAP_SERVERS: broker:29092
      CONFLUENT_METRICS_REPORTER_ZOOKEEPER_CONNECT: zookeeper:2181
      CONFLUENT_METRICS_REPORTER_TOPIC_REPLICAS: 1
      CONFLUENT_METRICS_ENABLE: 'true'
      CONFLUENT_SUPPORT_CUSTOMER_ID: 'anonymous'

I am reading metrics through MBeanServerConnection. The metrics I am interested in are kafka.server:type=BrokerTopicMetrics,name=BytesInPerSec. I can see the metrics exposed in Confluent Control Center (localhost:9021) but it seems like metrics are not available as MBean as jconsole only showing Kafka, kafka.producer, kafka.consumer, but no kafka.server