message: Add additional protobuf imports.
diff: @@ -22,6 +22,7 @@ limitations under the License.
  #include "google/protobuf/arena.h"
  #include "google/protobuf/compiler/importer.h"
  #include "google/protobuf/descriptor.h"
  +#include "google/protobuf/dynamic_message.h"
  #include "google/protobuf/io/coded_stream.h"
  #include "google/protobuf/io/zero_copy_stream.h"
  #include "google/protobuf/io/zero_copy_stream_impl_lite.h"
  