With --apt-upgrade, retry apt update a third time after one minute

With just a second try we still get occasional hash sum mismatches.
Recognize Qt plugins in the temp dir install tree

With that, autopilot tests work on images which don't have autopilot-qt
installed any more.
Track installed clicks in Tests object

With that we can do preparation steps in adt-run on already installed clicks.
Refactor AppArmor click update

Use a common new function apparmor_click() to set up AppArmor for a given list
of click packages, drop the more specific code from install tmp dir and
install_click, and configure all clicks in one go in run_test().

This also avoids the very expensive aa-clickhook -f to regenerate *all*
profiles (which takes 1.5 minutes).
ssh-setup/adb: Robustify powerd-cli invocation

It previously failed randomly.
ssh-setup/adb: Quiesce some noise from various phablet-config/gdbus/adb commands
adt-run: Make click apparmor setup more robust

In environments where clicks don't already have a profile, the touch will fail;
ignore that. Also simplify the creation of click-ap.rules to not require a
multi-line command, as this confuses some runners.
Remove the "adt-satdep" package after test installation finished

This avoids tests being confused about an unexpected package.
ssh-setup/adb: Add two missing $ADBOPTS
ssh-setup/adb: If the welcome wizard is already running, just kill that instead of the entire session

In particular, this avoids killing adb on both the host and the device.
ssh-setup/adb: Drop "autopilot --dbus-probe enable" call

It wastes some 1.5 minutes and is not needed any more, as we now reconfigure
AppArmor for the particular clicks that we want to test.
releasing package autopkgtest version 3.7
NullRunner.test_tmp_install_perl: Use a package from Ubuntu main

Fixes FTBFS in Ubuntu's buildds.
Fix AppArmor rule adjustment for a local click package