Giant Food Stores is releasing its first work under new agency Brownstein Group (BG) and it shifts away from promotional and deal-focused ads to a more story-telling narrative around customers' relationships with food.  The new campaign is rooted in research that finds the average American eats one out of every five meals in their car and 25% eat at least one fast-food meal a day. TV spots set the chain's new tone.  "The Dinner Table" shows how families typically center around this dining gathering place, even outside of eating. "The Smoothie" highlights how families can make healthier meal …