RIO DE JANEIRO — A task force led by Brazilian prosecutors said it rescued 163 Chinese nationals working in “slavery-like” conditions at a construction site in northeastern Brazil, where Chinese electric vehicle company BYD is building a factory. On Tuesday, the Labor Prosecutor’s Office released videos of the dorms where the construction workers were staying, which showed beds with no mattresses and rooms without any places for the workers to store their personal belongings. In a statement issued Monday, the prosecutor’s office said the workers had been hired in China by Jinjiang Construction Brazil, one of the contractors on the