Regarding presence of "Unattended-Upgrade::InstallOnShutdown" in /etc/apt/apt.conf.d/20auto-upgrades and /etc/apt/apt.conf.d/50unattended-upgrades:
It does not exist in /etc/apt/apt.conf.d/20auto-upgrades and it is commented out in /etc/apt/apt.conf.d/50unattended-upgrades ,
Eg: //Unattended-Upgrade::InstallOnShutdown "true";
Regarding presence of "Unattended- Upgrade: :InstallOnShutd own" in /etc/apt/ apt.conf. d/20auto- upgrades and /etc/apt/ apt.conf. d/50unattended- upgrades:
It does not exist in /etc/apt/ apt.conf. d/20auto- upgrades apt.conf. d/50unattended- upgrades ,
and it is commented out in /etc/apt/
Eg: //Unattended- Upgrade: :InstallOnShutd own "true";