Add size check to the Blivet test, too

needles/anaconda/partitioning/anaconda_part_size_changed_blivet.json

@@ -0,0 +1,15 @@
+{
+  "properties": [],
+  "tags": [
+    "anaconda_part_size_changed"
+  ],
+  "area": [
+    {
+      "xpos": 468,
+      "ypos": 323,
+      "width": 43,
+      "height": 16,
+      "type": "match"
+    }
+  ]
+}

tests/disk_custom_blivet_resize_lvm.pm

@@ -60,6 +60,8 @@ sub run {
     activate("root");
     custom_blivet_resize_partition(size => '13', units => 'GiB');
     wait_still_screen 5;
+    # Check that the value has been accepted by Anaconda
+    assert_screen "anaconda_part_size_changed";
 
     # Now format the resized root partition. It seems that the focus returns to the first
     # partition in the view, so we need to activate this again before we attempt to do