Jennifer Maas TV Business Writer When NBCUniversal kicks off TV’s traditional week of upfront presentations on Monday, picket-free sidewalks outside Radio City Music Hall will be a sight for sore eyes following last year’s noisy protests in the first weeks of what proved to be the nation’s “hot labor summer.” Hosting a programming presentation at a megawatt New York City venue like Radio City or Javits Center is stressful enough. Executives are eager to return to business as usual in wooing Madison Avenue.