Bump Confluent.Kafka from 1.9.3 to 2.0.2 (#325)

Bumps [Confluent.Kafka](https://github.com/confluentinc/confluent-kafka-dotnet) from 1.9.3 to 2.0.2.
- [Release notes](https://github.com/confluentinc/confluent-kafka-dotnet/releases)
- [Changelog](https://github.com/confluentinc/confluent-kafka-dotnet/blob/master/CHANGELOG.md)
- [Commits](confluentinc/confluent-kafka-dotnet@v1.9.3...v2.0.2)

---
updated-dependencies:
- dependency-name: Confluent.Kafka
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

src/common.props

@@ -21,7 +21,7 @@
     <NetCoreTestVersion>netcoreapp3.1</NetCoreTestVersion>
     <!-- Nuget package versions -->
     <AkkaVersion>1.4.49</AkkaVersion>
-    <KafkaVersion>1.9.3</KafkaVersion>
+    <KafkaVersion>2.0.2</KafkaVersion>
     <!-- Unit test Nuget package versions -->
     <XunitVersion>2.4.2</XunitVersion>
     <NBenchVersion>1.2.2</NBenchVersion>