Gael García Bernal still remembers that rush of electricity he felt on the set of “Y Tu Mamá También” more than 20 years ago. In the Amazon Prime movie Cassandro, Garcia Bernal plays Saul Armendariz, a gay amateur wrestler from El Paso, Texas, who rises to international stardom when he creates the character Cassandro, the `Liberace of Lucha Libre.’ “It …