Use JSON serialization for DLQ error messages instead of Ruby object inspection

[Copilot]

The DLQ error message in handle_dlq_response used Ruby's to_s on hashes, which changed format between JRuby 9 ("key"=>"value") and JRuby 10 ("key": "value"), causing brittle regex-based test assertions.

Changes

• lib/logstash/plugin_mixins/elasticsearch/common.rb: Replace string interpolation of action_params and response with LogStash::Json.dump(...), producing stable JSON output across JRuby versions:

  # Before
  detailed_message = "#{message} status: #{status}, action: #{action_params}, response: #{response}"
  # After
  detailed_message = "#{message} status: #{status}, action: #{LogStash::Json.dump(action_params)}, response: #{LogStash::Json.dump(response)}"

• spec/unit/outputs/elasticsearch_spec.rb: Replace the version-sensitive regex with straightforward include assertions on JSON key-value pairs:

  # Before — fragile, handles JRuby 9/10 differences
  expect(reason).to match /_id(?::| ?=>) ?"bar".*"foo" ?=> ?"bar".*response:.*"reason" ?=> ?"TEST"/
  # After — simple, format-agnostic
  expect(reason).to include '"_id":"bar"'
  expect(reason).to include '"foo":"bar"'
  expect(reason).to include '"reason":"TEST"'

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[elasticmachine]

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History

• 💚 Build #34 succeeded 507371d

cc @jsvd @Copilot