[autotests] Fix remaining autotests with failing border calculation

Summary:
As in 2c088894 fix remaining autotests failing since no borders has become
the new default behavior of Breeze.

Autotests should not rely on this default behavior of Breeze though, but be
run with a faked deco such that changes on Breeze does not directly change
the autotests behavior. That's a goal for the future.

Test Plan: 100% tests passed, 0 tests failed out of 147

Reviewers: #kwin, zzag

Reviewed By: #kwin, zzag

Subscribers: zzag, kwin

Tags: #kwin

Differential Revision: https://phabricator.kde.org/D21746