Okay found the solution. Using [0, 0, 0] as means and [1, 1, 1] as stdevs does what I want to do. It skips the normalization and results with the same Tensor as Python version.
float [] means = new float[] {0.0f, 0.0f, 0.0f};
float [] stds = new float[] {1.0f, 1.0f, 1.0f};
final Tensor inputTensor = TensorImageUtils.bitmapToFloat32Tensor(img, means, stds);

Why there is no bitmapToFloat32Tensor(img) function to skip normalization step ? Or did I miss it ?
Thanks for the help @IvanKobzarev !