Revert "Move import to header file"

This reverts commit 5c45b07c58.

examples/c++-dataflow/operator-rust-api/src/operator.cc

@@ -1,4 +1,5 @@
 #include "operator.h"
+#include "cxx-dataflow-example-operator-rust-api/src/lib.rs.h"
 #include <iostream>
 
 Operator::Operator() {}

examples/c++-dataflow/operator-rust-api/src/operator.h

@@ -1,6 +1,5 @@
 #pragma once
 #include "rust/cxx.h"
-#include "cxx-dataflow-example-operator-rust-api/src/lib.rs.h"
 #include <memory>
 
 class Operator