message: correct function name, use a more clear format for raw literal string
diff: @@ -27,6 +27,7 @@ limitations under the License.
  #include <utility>
  #include "absl/container/inlined_vector.h"
  +#include "absl/strings/str_format.h"
  #include "tensorflow/c/c_api.h"
  #include "tensorflow/c/tf_datatype.h"
  #include "tensorflow/c/tf_status.h"
  @@ -589,24 +590,21 @@ TEST(TestKernel, DeleteKernelBuilderIsOkOnNull) {
  TF_DeleteKernelBuilder(nullptr);
  }
  -std::string expected_string(const char* type) {
  - const auto expected_str = R"str(kernel {
  - op: "TypeOp)str" + std::string(type) +
  - std::string("\"") +
  - R"str(
  +std::string ExpectedString(const char* type) {
  + const auto format_str = R"str(kernel {
  + op: "TypeOp%s"
  device_type: "FakeDeviceName1"
  constraint {
  name: "T"
  allowed_values {
  list {
  - type: )str" + std::string(type) +
  - R"##(
  + type: %s
  }
  }
  }
  }
  -)##";
  - return expected_str;
  +)str";
  + return absl::StrFormat(format_str, type, type);
  }
  #define TEST_KERNEL_TYPE_CONSTRAINT(tf_type, dtype) \
  @@ -634,7 +632,7 @@ std::string expected_string(const char* type) {
  EXPECT_EQ(TF_OK, TF_GetCode(status)); \
  KernelList list; \
  list.ParseFromArray(buf->data, buf->length); \
  - ASSERT_EQ(expected_string(#dtype), list.DebugString()); \
  + ASSERT_EQ(ExpectedString(#dtype), list.DebugString()); \
  \
  TF_DeleteBuffer(buf); \
  TF_DeleteStatus(status); \
  