FIX: IMDb links were being oneboxed as posters (#13310)

IMDb movie links were being rendered as posters. This was because
IMDb was sending `og:type` as `image` randomly in some cases. To
fix this we'll now default all IMDb links as article type. This will
ensure that the IMDb onebox link includes all the information instead
of showing just a poster without any context.

spec/lib/onebox/engine/allowlisted_generic_onebox_spec.rb

@@ -182,4 +182,21 @@ describe Onebox::Engine::AllowlistedGenericOnebox do
       end
     end
   end
+
+  describe 'article html hosts' do
+    context 'returns article_html for hosts in article_html_hosts' do
+      before do
+        stub_request(:get, "https://www.imdb.com/title/tt0108002/")
+          .to_return(status: 200, body: onebox_response('imdb'))
+      end
+
+      it 'shows article onebox' do
+        onebox = described_class.new("https://www.imdb.com/title/tt0108002/")
+        expect(onebox.to_html).to include("https://www.imdb.com/title/tt0108002")
+        expect(onebox.to_html).to include("https://m.media-amazon.com/images/M/MV5BZGUzMDU1YmQtMzBkOS00MTNmLTg5ZDQtZjY5Njk4Njk2MmRlXkEyXkFqcGdeQXVyNjc1NTYyMjg@._V1_FMjpg_UX1000_.jpg")
+        expect(onebox.to_html).to include("Rudy (1993) - IMDb")
+        expect(onebox.to_html).to include("Rudy: Directed by David Anspaugh. With Sean Astin, Jon Favreau, Ned Beatty, Greta Lind. Rudy has always been told that he was too small to play college football.")
+      end
+    end
+  end
 end