Add yet another variant 'vdb selected' needle

This screen often seems to show slight variances in color,
really not sure why.

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

needles/anaconda/partitioning/blivet/anaconda_blivet_vdb_selected-lightblue-20190822.json

@@ -0,0 +1,15 @@
+{
+  "area": [
+    {
+      "xpos": 353,
+      "width": 51,
+      "ypos": 166,
+      "type": "match",
+      "height": 14
+    }
+  ],
+  "properties": [],
+  "tags": [
+    "anaconda_blivet_vdb_selected"
+  ]
+}