Add another variant Evince file select needle for Flatpak

For some reason the file can be highlighted/selected in blue as
well as grey. Well, whatever.

Signed-off-by: Adam Williamson <awilliam@redhat.com>

needles/gnome/apps/evince/evince_file_select_pdf-flatpak-blue-20230424.json

@@ -0,0 +1,15 @@
+{
+  "area": [
+    {
+      "ypos": 324,
+      "width": 68,
+      "height": 16,
+      "xpos": 257,
+      "type": "match"
+    }
+  ],
+  "properties": [],
+  "tags": [
+    "evince_file_select_pdf"
+  ]
+}