This reverts commit d48784e6 for causing nightly cron failures.

* Use nightly Fenix variant.

* Run the tests in PR.

* Update visual-metrics scripts to include the similarity metrics.

* Use python3.5 in visual-metrics docker.

* Install wget in the docker.

* Use python3.6 hashes instead of python3.5.

* Undo run-visual-metrics.py python changes.

* Upgrade python setuptools version to 46.1.3.

* Add setuptools to transitive dependency list.

* Undo PR test changes.

* Remove setuptools install line and use requirements.txt instead.

* Undo PR test changes.

* Fix geckodriver artifact suffix.

* Test a browsertime task.

* Revert browsertime test.

The drawable is sent to AddonsManagerAdapter.Style constructor and is displayed
near the add-on name if it is allowed to run in private browsing

Currently we support sorting by name and by last used. Also, the selected
option is saved in shared preferences so that the last option chosen by
the user is properly displayed even after the app was restarted.

RTL for toolbar are still missing