Move OpenJDKs install to proper place in Puppet and limit to Ubuntu

OpenJDK is installed from ci_tester and pkg_tester currently.
It isn't exactly the proper place, so this moves it to qt_prereqs.
Meanwhile, it's also moved from generally being installed in all
linux platforms to only being installed in Ubuntu, since OpenSuSE
doesn't need this.

Task-number: QTQAINFRA-745
Change-Id: If112e42c58bbd69da3af710ccda629b5972e04e7
Reviewed-by: Heikki Halmet <heikki.halmet@digia.com>