AppArmor: allow reading /proc/PID/{statm,smaps}

(Merging from upstream, where I pushed this change in the first place. In passing, the new alerting mechanism worked: https://gitlab.tails.boum.org/tails/torbrowser-launcher/-/pipelines/6218 :)

This is now needed at least for Firefox' memory reporter: https://bugzilla.mozilla.org/show_bug.cgi?id=1647957

Then tails!921 (merged) will take care of updating the submodule in tails/tails.