cni: log format byte array as string

[aojea]

Existing cni code logs the StdinData as an array of bytes, that is incomprensible for users checking the logs.

Format cni logs to convert the stdin byte aray to a string.

Example:

./cilium-testing-worker2/containerd.log:Jul 06 23:29:42 cilium-testing-worker2 containerd[106]: level=debug msg="Processing CNI ADD request &skel.CmdArgs{ContainerID:"8e1464e2eba2853979365f7b40ad30826f3e5060e9d3cee93ada262306e9be5b", Netns:"/var/run/netns/cni-0e9e8042-fb78-a4fc-c4fa-549f6f44c007", IfName:"eth0", Args:"K8S_POD_UID=41ae5812-0b9b-4b9f-a9fc-a33db9111522;IgnoreUnknown=1;K8S_POD_NAMESPACE=netpol-x-3947;K8S_POD_NAME=c;K8S_POD_INFRA_CONTAINER_ID=8e1464e2eba2853979365f7b40ad30826f3e5060e9d3cee93ada262306e9be5b", Path:"/opt/cni/bin", StdinData:[]uint8{0x7b, 0x22, 0x63, 0x6e, 0x69, 0x56, 0x65, 0x72, 0x73, 0x69, 0x6f, 0x6e, 0x22, 0x3a, 0x22, 0x30, 0x2e, 0x33, 0x2e, 0x31, 0x22, 0x2c, 0x22, 0x65, 0x6e, 0x61, 0x62, 0x6c, 0x65, 0x2d, 0x64, 0x65, 0x62, 0x75, 0x67, 0x22, 0x3a, 0x74, 0x72, 0x75, 0x65, 0x2c, 0x22, 0x6c, 0x6f, 0x67, 0x2d, 0x66, 0x69, 0x6c, 0x65, 0x22, 0x3a, 0x22, 0x2f, 0x76, 0x61, 0x72, 0x2f, 0x72, 0x75, 0x6e, 0x2f, 0x63, 0x69, 0x6c, 0x69, 0x75, 0x6d, 0x2f, 0x63, 0x69, 0x6c, 0x69, 0x75, 0x6d, 0x2d, 0x63, 0x6e, 0x69, 0x2e, 0x6c, 0x6f, 0x67, 0x22, 0x2c, 0x22, 0x6e, 0x61, 0x6d, 0x65, 0x22, 0x3a, 0x22, 0x70, 0x6f, 0x72, 0x74, 0x6d, 0x61, 0x70, 0x22, 0x2c, 0x22, 0x74, 0x79, 0x70, 0x65, 0x22, 0x3a, 0x22, 0x63, 0x69, 0x6c, 0x69, 0x75, 0x6d, 0x2d, 0x63, 0x6e, 0x69, 0x22, 0x7d}}" eventUUID=c15eb614-f63a-44af-9f17-640712ce8b1d subsys=cilium-cni

[aojea]

/assign @aanm @squeed

[tklauser]

/test