May the odds be ever in her favor. Jennifer Lawrence finally joined Instagram — but the “Hunger Games” alum may not be sticking around if fans have “anything negative” to say. “So yeah, I’m giving it a shot,” Lawrence, 36, said in her debut post on the social media platform. “And if anyone says anything negative, I will quit immediately. No questions asked. If anyone thinks something mean, I’ll know. I’ll know, and I’ll quit.” The Oscar winner issued the threat while lounging in bed in a white satin robe. She later took to her Instagram Stories — for the first time — to warn followers that “any mean or aggressive comments” could negatively…