Fixes commands not working without sudo (#17139)

In doc of kubeadm installation, there are commands which wont work
without sudo regarding to Ubuntu/Debian instruction. However, other
docs related to kubeadm under
content/en/docs/setup/production-environment have commands with sudo.

This commit fixes this inconsistency.

content/en/docs/setup/production-environment/tools/kubeadm/install-kubeadm.md

@@ -66,10 +66,10 @@ switching to legacy mode, and is therefore incompatible with current kubeadm pac
 {{< tabs name="iptables_legacy" >}}
 {{% tab name="Debian or Ubuntu" %}}
 ```bash
-update-alternatives --set iptables /usr/sbin/iptables-legacy
-update-alternatives --set ip6tables /usr/sbin/ip6tables-legacy
-update-alternatives --set arptables /usr/sbin/arptables-legacy
-update-alternatives --set ebtables /usr/sbin/ebtables-legacy
+sudo update-alternatives --set iptables /usr/sbin/iptables-legacy
+sudo update-alternatives --set ip6tables /usr/sbin/ip6tables-legacy
+sudo update-alternatives --set arptables /usr/sbin/arptables-legacy
+sudo update-alternatives --set ebtables /usr/sbin/ebtables-legacy
 ```
 {{% /tab %}}
 {{% tab name="Fedora" %}}
@@ -177,14 +177,14 @@ For more information on version skews, see:
 {{< tabs name="k8s_install" >}}
 {{% tab name="Ubuntu, Debian or HypriotOS" %}}
 ```bash
-apt-get update && apt-get install -y apt-transport-https curl
-curl -s https://packages.cloud.google.com/apt/doc/apt-key.gpg | apt-key add -
-cat <<EOF >/etc/apt/sources.list.d/kubernetes.list
+sudo apt-get update && sudo apt-get install -y apt-transport-https curl
+curl -s https://packages.cloud.google.com/apt/doc/apt-key.gpg | sudo apt-key add -
+cat <<EOF | sudo tee /etc/apt/sources.list.d/kubernetes.list
 deb https://apt.kubernetes.io/ kubernetes-xenial main
 EOF
-apt-get update
-apt-get install -y kubelet kubeadm kubectl
-apt-mark hold kubelet kubeadm kubectl
+sudo apt-get update
+sudo apt-get install -y kubelet kubeadm kubectl
+sudo apt-mark hold kubelet kubeadm kubectl
 ```
 {{% /tab %}}
 {{% tab name="CentOS, RHEL or Fedora" %}}