SAN DIEGO—Contract negotiations are scheduled to resume on March 30 after thousands of grocery workers across Southern California voted to authorize their union to call a strike against the owners of stores including Ralphs and Vons/Pavilions/Albertsons. The “yes” vote does not automatically result in a strike—it only authorizes the union to call one if no progress is made in labor negotiations. Roughly 47,000 workers represented by seven United Food and Commercial Workers local unions between Central California and the Mexico border were eligible to cast ballots. The membership covers workers at more than 500 stores. Voting began last Monday with the results announced Saturday. “Through the past two years of the pandemic, it was the hard work and sacrifice of our members that helped these … companies earn billions in profits,” read a statement from all seven unions. “As we continue at the bargaining table, all of our Local Unions …