message: LSC: Apply bugprone-stringview-nullptr across the codebase to remove undefined behavior
  Callsites matched by the bugprone-stringview-nullptr check are calling the single-parameter `const char*` constructor of `string_view`. This constructor uses C-string semantics, meaning it does not support the null case. Passing null results in undefined behavior.
diff: @@ -123,7 +123,7 @@ StatusOr<std::vector<LabelMapItem>> GetLabelMapIfAny(
  ModelMetadataExtractor::FindFirstAssociatedFileName(
  tensor_metadata, tflite::AssociatedFileType_TENSOR_AXIS_LABELS,
  locale);
  - absl::string_view display_names_file = nullptr;
  + absl::string_view display_names_file = {};
  if (!display_names_filename.empty()) {
  ASSIGN_OR_RETURN(display_names_file, metadata_extractor.GetAssociatedFile(
  display_names_filename));
  