[AMQ Streams] Kafka Connect metrics fails with FileNotFoundException: /opt/kafka/custom-config/metrics-config.yml (No such file or directory)

Issue

• Kafka Connect metrics fails with the following error:

  Exception in thread "main" java.lang.reflect.InvocationTargetException
  at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
  at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
  at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
  at java.base/java.lang.reflect.Method.invoke(Method.java:566)
  at java.instrument/sun.instrument.InstrumentationImpl.loadClassAndStartAgent(InstrumentationImpl.java:513)
  at java.instrument/sun.instrument.InstrumentationImpl.loadClassAndCallPremain(InstrumentationImpl.java:525)
  Caused by: java.io.FileNotFoundException: /opt/kafka/custom-config/metrics-config.yml (No such file or directory)
  at java.base/java.io.FileInputStream.open0(Native Method)
  at java.base/java.io.FileInputStream.open(FileInputStream.java:219)
  at java.base/java.io.FileInputStream.(FileInputStream.java:157)
  at java.base/java.io.FileReader.(FileReader.java:75)
  at io.prometheus.jmx.shaded.io.prometheus.jmx.JmxCollector.(JmxCollector.java:78)
  at io.prometheus.jmx.shaded.io.prometheus.jmx.JavaAgent.premain(JavaAgent.java:29)
  ... 6 more
  *** java.lang.instrument ASSERTION FAILED ***: "result" with message agent load/premain call failed at         ./src/java.instrument/share/native/libinstrument/JPLISAgent.c line: 422
  FATAL ERROR in native method: processing of -javaagent failed, processJavaStart failed
  

• The kafka connect metrics is looking for metrics-config.yaml instead of metrics-config.json.