To reproduce, run mvn compile

Expected: only AutoValue_DuplicateSpannerConfig in target/classes/org/apache/beam/sdk/io/gcp/spanner/

Actual: there are many AutoValue_* classes, seemingly regenerated from binaries in beam-sdks-java-io-google-cloud-platform in target/classes/org/apache/beam/sdk/io/gcp/spanner/.

Comment: this has caused inconsistent class path in DataflowTemplates: GoogleCloudPlatform/DataflowTemplates#1362