HDDS-5414. Data buffers incorrectly filtered for Ozone Insight

[adoroszlai]

What changes were proposed in this pull request?

Fix the issue that Ozone Insight prints binary data for dataBuffers:

[TRACE|org.apache.hadoop.ozone.container.common.impl.HddsDispatcher|OzoneProtocolMessageDispatcher] [service=DatanodeClient] [type=ReadChunk] request is processed. Response:
cmdType: ReadChunk
traceID: ""
result: SUCCESS
readChunk {
  ...
  dataBuffers {
    buffers: "4w7u1Zp8@{"
    buffers: "<redacted>"
  }
}

This is caused by appending to the list of buffers in processForDebug instead of replacing the list with a single item.

https://issues.apache.org/jira/browse/HDDS-5414

How was this patch tested?

Added unit test. Also tested on compose-based cluster:

# console 1
ozone insight logs -v datanode.dispatcher -f datanode=ozone_datanode_1

# console 2
ozone freon ockg -n10 -t1 -p test -s 10
ozone freon ockv -n10 -t1 -p test

Output:

[TRACE|org.apache.hadoop.ozone.container.common.impl.HddsDispatcher|OzoneProtocolMessageDispatcher] [service=DatanodeClient] [type=ReadChunk] request is processed. Response:
cmdType: ReadChunk
traceID: ""
result: SUCCESS
readChunk {
  ...
  dataBuffers {
    buffers: "<redacted>"
  }
}

[hanishakoneru]

+1
Thanks for fixing this @adoroszlai.

[adoroszlai]

Thanks @hanishakoneru for the review.