fix shutdown_test

test/cpp/end2end/shutdown_test.cc

@@ -39,7 +39,7 @@
 #include "test/cpp/util/echo.grpc.pb.h"
 #include "src/core/support/env.h"
 #include <grpc++/channel_arguments.h>
-#include <grpc++/channel_interface.h>
+#include <grpc++/channel.h>
 #include <grpc++/client_context.h>
 #include <grpc++/create_channel.h>
 #include <grpc++/credentials.h>
@@ -118,7 +118,7 @@ class ShutdownTest : public ::testing::Test {
   }
 
  protected:
-  std::shared_ptr<ChannelInterface> channel_;
+  std::shared_ptr<Channel> channel_;
   std::unique_ptr<grpc::cpp::test::util::TestService::Stub> stub_;
   std::unique_ptr<Server> server_;
   bool shutdown_;