First there was Apu, the stereotypical convenience store owner parodied on “The Simpsons.” Then there was Kumar, the brilliant stoner-slacker of the “Harold and Kumar” films. Now the latest character to test the good humor of Indian Americans is Mike Myers’ “The Love Guru,” a narcissistic, sucker-punching spiritual leader whose goals in life are to meet girls and appear on “Oprah.” Enough is enough, some Hindu activists are saying. Lampooning a guru, a revered spiritual teacher in Hindu tradition, crosses the line from acceptable social satire to mockery of a minority religious culture little understood by Americans, they say.