Allow RandomUniform to be quantized. As the RandomUniform operator is a

custom op, it is up to the tf-lite user to provide the implementation. Best to
assume it exists so the user can implement.

PiperOrigin-RevId: 225228337

tensorflow/lite/toco/graph_transformations/quantize.cc

@@ -64,6 +64,7 @@ bool SupportsQuantization(const Operator& op) {
          type == OperatorType::kRelu1 || type == OperatorType::kRelu6 ||
          type == OperatorType::kShape || type == OperatorType::kExpandDims ||
          type == OperatorType::kPack || type == OperatorType::kTopK_V2 ||
+         type == OperatorType::kRandomUniform ||
          type == OperatorType::kResizeNearestNeighbor ||
          type == OperatorType::kPRelu;
 }