Update prom/prometheus Docker tag to v2.15.2
Update prom/prometheus Docker tag to v2.15.2

faucetsdn/faucet,trungdtbk/faucet,anarkiwi/faucet,REANNZ/faucet,trungdtbk/faucet,faucetsdn/faucet,anarkiwi/faucet,REANNZ/faucet,shivarammysore/faucet,mwutzke/faucet,shivarammysore/faucet,gizmoguy/faucet,gizmoguy/faucet,mwutzke/faucet