[apparmor] what is the best way to write apparmor dbus rules

[Alexandre Pujol]

Thanks John,

Following your advice, I rewritten all my old dbus rules. I have added 
over 30 new dbus specific abstractions [1]. As I have the endpoint, they 
are all labelled with they corresponding apparmor profile. These 
abstractions should be used by profiles that simply need to talk to a 
given interface, so I restricted the allowed method.

For example, most common polkit communication can be allowed with:
```
   include <abstractions/bus/org.freedesktop.PolicyKit1>
```

They will be still some polishing work to do but we finally have a good 
base.

[1]: 
https://github.com/roddhjav/apparmor.d/tree/main/apparmor.d/abstractions/bus

Regards,
Alex