tweak two disk matching to be more robust

Summary:
Depending on the disks attached to the system and some other
idiosyncracries (like what the disk 'description' currently
happens to be), the distance between the two disk icons can
vary, so a needle that matches on the two disk icons is fragile
(whenever the distance differs, the match fails). So instead of
that, let's have a needle that matches on a single icon with
a lot of grey space to its left, plus the two little matches
we later use in the select_disk(1/2) needles. This should be
robust enough and doesn't need us to keep duplicating it when
the distance between the icons changes. With this tweak, the
'2' variant is no longer needed.

Test Plan:
Run the various tests that use two disks and check this
needle always matches. You'll also want to have D456 applied.

Reviewers: garretraziel, jskladan

Reviewed By: garretraziel, jskladan

Subscribers: tflink

Differential Revision: https://phab.qadevel.cloud.fedoraproject.org/D463

needles/anaconda_install_destination_two_disks.json

@@ -3,9 +3,23 @@
         {
             "height": 46,
             "type": "match",
-            "width": 322,
-            "xpos": 57,
+            "width": 162,
+            "xpos": 122,
             "ypos": 213
+        },
+        {
+            "height": 24,
+            "type": "match",
+            "width": 17,
+            "xpos": 41,
+            "ypos": 289
+        },
+        {
+            "height": 23,
+            "type": "match",
+            "width": 15,
+            "xpos": 206,
+            "ypos": 290
         }
     ],
     "tags": [

needles/anaconda_install_destination_two_disks2.json

@@ -1,18 +0,0 @@
-{
-  "tags": [
-    "anaconda_install_destination_two_disks",
-    "ENV-DISTRI-fedora",
-    "ENV-INSTLANG-en_US",
-    "ENV-FLAVOR-server"
-  ],
-  "area": [
-    {
-      "height": 46,
-      "width": 260,
-      "ypos": 216,
-      "type": "match",
-      "xpos": 59
-    }
-  ],
-  "properties": []
-}