* Add Ubuntu 20.04 to CI (#1658)
* Add Ubuntu 20.04 to CI.
* Skip mqtt test on Ubuntu 20.04.
* Use explicit disable instead of aliases.
* Add Ubuntu 20.04 specific config for setup_postgresql_db.
* Fix postgres version.
(cherry picked from commit 4223f48d38)
* Adjust AZP config.
* Remove some tests.
* Make more similar to config fromm main branch.