Add test case for 3 control plane nodes and internal load balancer#1550

bochengchu wants to merge 2 commits intokubernetes-sigs:mainkubernetes-sigs/cluster-api-provider-gcp:mainfrom

bochengchu:e2e-3cpbochengchu/cluster-api-provider-gcp:e2e-3cpCopy head branch name to clipboard