policy: restrict port to be base 10 in visibility annotation
policy: restrict port to be base 10 in visibility annotation

Signed-off by: Ian Vernon <ian@cilium.io>

cilium-team/cilium,michi-covalent/cilium,michi-covalent/cilium,cilium-team/cilium,tklauser/cilium,cilium/cilium,tgraf/cilium,tgraf/cilium,tgraf/cilium,tgraf/cilium,tklauser/cilium,michi-covalent/cilium,michi-covalent/cilium,tklauser/cilium,tklauser/cilium,tklauser/cilium,tgraf/cilium,tgraf/cilium,michi-covalent/cilium,cilium/cilium,cilium/cilium,cilium/cilium,cilium/cilium