Summary:
In this test we are waiting on 4 events. 2 things via 2 threads. It was
unstable.

This patch avoids hardcoding a bunch of ifs() handling recieving
different orders, by waiting for both events.

We can't use QTRY_COMPARE as ConnectionThread does magic things with
QCoreApplication::eventDispatcher which don't work quite the same.

This is a bit of a shot in the dark. It passes 100% of the time locally,
lets see what CI manages to do :)

Test Plan: Ran test :)

Reviewers: #kwin, zzag

Reviewed By: #kwin, zzag

Subscribers: zzag, kde-frameworks-devel

Tags: #frameworks

Differential Revision: https://phabricator.kde.org/D28892