If “Roman J. Israel, Esq.” is remembered for anything, it will be for the chance it gives Denzel Washington to do a pure character role. Here he’s nerdy and socially maladroit and has weird hair; and for the first 10 minutes, you might assume the movie is set in the 1990s or even the ’70s: He wears huge glasses, his ties are fat and his lapels are enormous. But no, this is a modern-day story about a man out of his time, a lawyer who had his formative experiences in the 1970s and has never really changed.