A waterfront amphitheater roughly twice the size of the Greek Theatre and two-thirds the size of the Hollywood Bowl is set to open this week in Long Beach — and there’s a lot riding on its success. City leaders hope F&M Bank Amphitheater of Long Beach, located next to the famed Queen Mary, will supplant declining revenues from oil extraction and lead to an uptick in tourism. Concert promoters, meanwhile, see it as filling an important gap in Southern California’s music venue market. The temporary amphitheater, which has a maximum capacity of 11,000, is meant to be a precursor to a permanent “Long Beach Bowl,” which is being pitched as the largest waterfront venue on the West Coast. The site opens June 6 with a performance by native son Snoop Dogg, and is expected to last for up to 10 years. The new amphitheater represents a years-long dream of Mayor Rex Richardson, who began championing an outdoor performance venue on the waterfront in 2023. Soon after the closure of Irvine’s FivePoint Amphitheatre in October of …