message: Add option to use non static lib in ios benchmark app.
diff: #import <string>
  #import <vector>
  +#if defined(USE_TFLITE_BENCHMARK_HEADERS)
  +#include "tensorflow/lite/tools/benchmark/experimental/c/benchmark_c_api.h"
  +#include "tensorflow/lite/tools/benchmark/logging.h"
  +#else
  #import <TensorFlowLiteBenchmarkC/TensorFlowLiteBenchmarkC.h>
  +#endif
  namespace {
  NSString* FilePathForResourceName(NSString* filename) {
  