What is happening?
Skype is installed as a snap. This means skype runs in a security sandbox. The logs you see are from the sandbox, stating that skype is trying to do stuff that is not allowed.
How do I solve this?
Those specific error messages can be solved by giving skype access to network-observe.
sudo snap connect skype:network-observe
However, there are a couple of other error messages that you can't solve as a user. These are caused by Skype accessing things that it doesn't need. The Skype developers should take a look at these denials and change the application to stop accessing those resources.
Is there really no way to turn off these messages?
You can turn of all denials from the snap sandbox for all apps by running the following command:
echo -n quiet_denied > /sys/module/apparmor/parameters/audit
This will suppress denial warnings until the next boot.
If you want to make this permanent, you will have to specify a kernel parameter using grub. Warning: this is an advanced change, this might brick your system if you don't know what you're doing and mess it up!
In the file /etc/default/grub, add apparmor.audit=quiet_denied at the back of GRUB_CMDLINE_LINUX_DEFAULT, like so:
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash apparmor.audit=quiet_denied"
Then run
sudo update-grub
and reboot.
