message: Fix a bug in tf.strided_slice()
  Current implementation modifies TfLiteNode::builtin_data every time when
  a loaded graph is executed. The three masks in params will continually
  flipping, and cause the op produce incorrect result every two executions.
diff: @@ -48,7 +48,7 @@ struct StridedSliceContext {
  output = GetOutput(context, node, kOutputTensor);
  dims = NumDimensions(input);
  }
  - TfLiteStridedSliceParams* params;
  + const TfLiteStridedSliceParams* params;
  TfLiteTensor* input;
  TfLiteTensor* begin;
  TfLiteTensor* end;
  @@ -199,18 +199,18 @@ TfLiteStatus Eval(TfLiteContext* context, TfLiteNode* node) {
  strides.emplace_back(1);
  }
  - op_context.params->begin_mask =
  + int begin_mask =
  ReverseMaskBits(op_context.params->begin_mask, op_context.dims);
  - op_context.params->end_mask =
  + int end_mask =
  ReverseMaskBits(op_context.params->end_mask, op_context.dims);
  - op_context.params->shrink_axis_mask =
  + int shrink_axis_mask =
  ReverseMaskBits(op_context.params->shrink_axis_mask, op_context.dims);
  #define TF_LITE_STRIDED_SLICE(kernel_type, data_type) \
  kernel_type::StridedSlice( \
  GetTensorData<data_type>(op_context.input), \
  - GetTensorDims(op_context.input), op_context.params->begin_mask, \
  - op_context.params->end_mask, op_context.params->shrink_axis_mask, \
  + GetTensorDims(op_context.input), \
  + begin_mask, end_mask, shrink_axis_mask, \
  starts, stops, strides, GetTensorData<data_type>(op_context.output), \
  GetTensorDims(op_context.output))
  