Giants-Browns flexed to ‘Sunday Night Football’ over miserable Cowboys

Time was when the Cowboys were scheduled to play a prime-time game, they always played at that time. Flexing out the ratings-gold Cowboys to an earlier television slot? No way. Yes way. The Giants-Browns game on Dec. 20 in Week 15, originally scheduled for 1 p.m. at MetLife Stadium, has been flexed into the 8:20…