message: Compilation issue: 'string' was not declared in this scope
  ```tensorflow/lite/testing/kernel_test/generate_diff_report.cc:22:3: error: 'string' was not declared in this scope
  string base, test, output;
  ^~~~~~```
  The above compilation error is fixed.
diff: @@ -19,7 +19,7 @@ limitations under the License.
  #include "tensorflow/lite/testing/kernel_test/diff_analyzer.h"
  int main(int argc, char** argv) {
  - string base, test, output;
  + std::string base, test, output;
  std::vector<tensorflow::Flag> flag_list = {
  tensorflow::Flag("base", &base, "Path to the base serialized tensor."),
  tensorflow::Flag("test", &test, "Path to the test serialized tensor."),
  