Already looking like a hit with Broadway theatergoers, newcomer On Your Feet! — the biotuner about the courtship and rise to superstardom of the Miami Sound Machine’s Gloria and Emilio Estefan — got a priceless plug Thursday morning, leading off NBC’s coverage of the Macy’s Thanksgiving Day Parade. Led by star-in-the-making Ana Villafane as Gloria singing “Conga” and “Turn The Beat Around,” the show got the kind of exposure no 30-second spot could bring.