plugins/cilium-cni: add Interface Index to the CNI result
plugins/cilium-cni: add Interface Index to the CNI result

This add the corresponding Interface index to the CNI result.

CNI plugins like tc-redirect-tap expects this field to be filled.

Signed-off-by: Salvatore Mazzarino <34c6fceca75e456f25e7e99531e2425c6c1de443@mazzarino.cz>

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