e2e: expand ingress prometheus test assertions
e2e: expand ingress prometheus test assertions

Check for some important metrics keys which are a decent proxy for readiness.

gabemontero/origin,jeremyeder/origin,sjug/origin,JacobTanenbaum/origin,jeremyeder/origin,dinhxuanvu/origin,dinhxuanvu/origin,coreydaley/origin,ironcladlou/origin,hroyrh/origin,hroyrh/origin,tnozicka/origin,ironcladlou/origin,csrwng/origin,jsafrane/origin,gabemontero/origin,gabemontero/origin,soltysh/origin,pecameron/origin,sallyom/origin,jim-minter/origin,jsafrane/origin,tnozicka/origin,mahak/origin,nak3/origin,coreydaley/origin,deads2k/origin,xiuwang/origin,pecameron/origin,ironcladlou/origin,dinhxuanvu/origin,jeremyeder/origin,spadgett/origin,coreydaley/origin,mfojtik/origin,mkumatag/origin,csrwng/origin,mahak/origin,nak3/origin,mkumatag/origin,pweil-/origin,xiuwang/origin,sallyom/origin,akram/origin,jim-minter/origin,JacobTanenbaum/origin,bparees/origin,deads2k/origin,mahak/origin,pweil-/origin,jeremyeder/origin,tnozicka/origin,mfojtik/origin,Miciah/origin,sjug/origin,deads2k/origin,tnozicka/origin,spadgett/origin,enj/origin,jsafrane/origin,tnozicka/origin,dinhxuanvu/origin,sdminonne/origin,bparees/origin,jeremyeder/origin,sallyom/origin,akram/origin,ingvagabund/origin,akram/origin,ingvagabund/origin,spadgett/origin,mkumatag/origin,pecameron/origin,sdminonne/origin,openshift/origin,Miciah/origin,enj/origin,spadgett/origin,ingvagabund/origin,csrwng/origin,pweil-/origin,sjug/origin,xiuwang/origin,jim-minter/origin,dinhxuanvu/origin,enj/origin,hroyrh/origin,bparees/origin,nak3/origin,tnozicka/origin,JacobTanenbaum/origin,spadgett/origin,soltysh/origin,mfojtik/origin,Miciah/origin,openshift/origin,soltysh/origin,openshift/origin,sdminonne/origin