message: Add 'const' in a couple of places where it was missing.
diff: @@ -23,8 +23,8 @@ limitations under the License.
  namespace {
  -TfLiteRegistration* GetDummyRegistration() {
  - static TfLiteRegistration registration = {
  +const TfLiteRegistration* GetDummyRegistration() {
  + static const TfLiteRegistration registration = {
  /*init=*/nullptr,
  /*free=*/nullptr,
  /*prepare=*/nullptr,
  