See googleapis/gapic-showcase#1385

• Update to the new Showcase version that provides this new RPC
• Add a Showcase integration test (https://github.com/googleapis/sdk-platform-java/tree/main/showcase/gapic-showcase/src/test/java/com/google/showcase/v1beta1/it) to exercise this feature and verify the client can process Any fields whose actual types are those in error_details.proto.
• If the client does not support this behavior, either provide a fix by updating gapic-generator-java or open a ticket describing the changes needed.
  [sdk-platform-java] Handle google.rpc.ErrorInfo in HttpJson*Stub class google-cloud-java#12465