Open this photo in gallery: President Donald Trump speaks to reporters on the South Lawn of the White House after arriving in Washington on May 4.TIERNEY L. CROSS/The New York Times News Service For the past few months, Jon Voight has been quietly taking meetings with U.S. studio executives and entertainment-industry unions as the actor – perhaps best known today for biting the arm of Cosmo Kramer – tries to fulfill his mandate as one of U.S. President Donald Trump’s “special ambassadors” to the film industry. (The other two unofficial envoys, announced by Trump in January, are Sylvester Stallone and…