fix(display): tests

Author: git-f0x

cosmic-settings/src/pages/display/mod.rs

@@ -398,6 +398,7 @@ impl page::Page<crate::pages::Message> for Page {
                 enabled: true,
                 make: None,
                 model: "Test 1".into(),
+                serial_number: "Serial 1".into(),
                 mirroring: None,
                 physical: (1, 1),
                 position: (0, 0),
@@ -415,6 +416,7 @@ impl page::Page<crate::pages::Message> for Page {
                 enabled: true,
                 make: None,
                 model: "Test 1".into(),
+                serial_number: "Serial 2".into(),
                 mirroring: None,
                 physical: (1, 1),
                 position: (1920, 0),