OK, we once again hit an annoying case where the button match
that doesn't include text got matched in the sidebar:
https://openqa.fedoraproject.org/tests/39576#step/_do_install_and_reboot/13
so I think it's time to give up on that approach and just go
ahead and deal with the button text varying between live and
traditional installs. So let's change the existing needles to
include the button text and add one new needle to cover the
English live F25/F26 case. I don't think we need a 'quit'
needle for F24 (as the only thing we test for F24 is the Atomic
installer image, which says 'Reboot') or for French or Russian
(as we only test a traditional installer image for those, not
a live image).