CHICAGO — When mid-July rolls around, Chicago-based and raised actor Amy Morton typically starts work on a new, 22-episode season of the long-running NBC series “Chicago P.D.,” on which she plays the zero-nonsense Sgt. Trudy Platt. But this is no typical mid-July. Earlier this summer, an overwhelming majority of members of the SAG-AFTRA and WGA unions, representing primarily small- and ...