only swipe to remove artile with unread filter

[aeghn]

(cherry picked from commit c35fe96)

[mbestavros]

@aeghn Could you elaborate on what this change is supposed to do? I tried the swipe to dismiss gesture, and it worked in both "All" and "Unread" feeds with your patch applied.

[nvllz]

@mbestavros it's about not dismissing articles in "All" and "Starred" Flow pages. So you can dismiss it from "Unread" Flow, but as it's still supposed to be shown in "All", it's only marked as read instead of disappearing when you swipe on some article from there. I've been using a custom build with this code for months and can confirm it works well.

[mbestavros]

@nvllz I don't know what I did to test it last time, but when revisiting it now, it works perfectly, just as described. And the new behavior applies to every view within the "All" tab (ie. all articles, a category, and an individual feed), which is what we want.

Let's merge it! Thanks for the contribution @aeghn!