appgw: validate cert only if certificateFile is specified in set ssl cert command#10991

akshaysngupta wants to merge 5 commits intoAzure:network-marchAzure/azure-powershell:network-marchfrom

akshaysngupta:aksgupta/fix/sslakshaysngupta/azure-powershell:aksgupta/fix/sslCopy head branch name to clipboard