Fix a potential race in desktop update test
    
    https://openqa.stg.fedoraproject.org/tests/424393 is a failure
    where the 'Download' [updates] button was already visible when
    we went to the tab. We already checked whether an 'apply' button
    is visible and skipped the 'refresh' click if so, but because
    the 'download' button is a new thing, we weren't skipping the
    'refresh' click if 'download' was already visible.
    
    So in this case, even though we could already see 'download', we
    went ahead and clicked 'refresh'...then *immediately* started
    looking for 'download'. It seems that Software did not refresh
    and remove the 'Download' button *immediately* when we pressed
    'refresh' - it left the 'Download' button visible briefly, and
    *in this brief window*, we clicked it. *Then* Software kinda
    'noticed' we'd clicked 'Update', and it seems it just sort of
    throws away our click on 'Download' at that point and does the
    refresh.
    
    So at that point, the test thinks it's clicked 'Download' and
    expects to see 'Apply', but actually the 'Download' click got
    more or less thrown away, so the test fails, sitting at the
    'Download' button.
    
    To solve this, let's just extend the existing check to skip the
    'refresh' click if 'download' *or* 'apply' are already visible.
    
    There is a sort of possibility here that we could wind up
    downloading and installing some updates that existed and were
    noticed *before* we did our python3-kickstart trick, but not
    install the python3-kickstart update, and cause the test to fail
    because of that, but that doesn't seem to have happened before
    when we were seeing the 'update' button, so I think I'm not
    going to borrow trouble. If it happens, we'll deal with it I
    guess.
    
    The comment talks only about KDE, but clearly it can be the case
    that an automatic check makes the button visible on GNOME too,
    so let's rewrite the comment too.
    
    Signed-off-by: Adam Williamson <awilliam@redhat.com>