kali_toggle_auto_dns.sh

echo "Writing a script to toggle the settings (~/toggle_dns.sh)..."

if echo "#!/bin/bash
if grep -Fxq \"dns=none\" /etc/NetworkManager/NetworkManager.conf
then
	echo \"[main]
plugins=ifupdown,keyfile

[ifupdown]
managed=false\" > /etc/NetworkManager/NetworkManager.conf
else
	echo \"[main]
plugins=ifupdown,keyfile
dns=none
rc-manager=unmanaged

[ifupdown]
managed=false\" > /etc/NetworkManager/NetworkManager.conf

	echo \"nameserver 8.8.8.8
nameserver 1.1.1.1
nameserver 8.8.4.4\" > /etc/resolv.conf
fi
systemctl restart NetworkManager" > ~/toggle_dns.sh

then 
	chmod +x ~/toggle_dns.sh
	
	echo "Creating a desktop shortcut..."

	if echo "[Desktop Entry]
	Version=1.0
	Type=Application
	Name=Toggle auto DNS
	Comment=
	Exec=pkexec /home/$USER/toggle_dns.sh
	Icon=
	Path=
	Terminal=true
	StartupNotify=false" > ~/Desktop/Toggle\ auto\ DNS\.desktop

	then

		chmod +x ~/Desktop/Toggle\ auto\ DNS\.desktop
		echo "
All done. There should be a new icon on the desktop which you can use to toggle between automatic and manual DNS settings. Or, e.g. if you are not using a GUI, you can run the script directly with ~/toggle_dns.sh."

	else

		echo "Coudln't create the shortcut"

	fi
	
else
	echo "Couldn't create the script."
fi

One-liner to install:

rm -rf ~/kali_toggle_auto_dns; git clone https://gist.github.com/abf01acd5783162a99765ff226ef0b33.git ~/kali_toggle_auto_dns && chmod +x ~/kali_toggle_auto_dns/kali_toggle_auto_dns.sh && ~/kali_toggle_auto_dns/kali_toggle_auto_dns.sh && rm -rf ~/kali_toggle_auto_dns