Jennifer Maas TV Business WriterWarnerMedia has been owned by telco giant AT&T for less than four years and it will soon have a new parent company — likely by the end of next month.Discovery’s shareholder vote on the acquisition of WarnerMedia is set for today during a special meeting of stockholders set for 10 a.m. ET. The deal is expected to get an easy thumbs-up given the approval already bestowed by Discovery’s oldest and most influential holders, investor John Malone and Advance/Newhouse Co.