Doc changes: add helm flags when installing aws load balancer controllerm on managed node group to avoid IMDS denied error#1113

rookieeew wants to merge 2 commits intoawsdocs:mainlineawsdocs/amazon-eks-user-guide:mainlinefrom

rookieeew:lbc-helm-flagrookieeew/amazon-eks-user-guide:lbc-helm-flagCopy head branch name to clipboard