test: update theme tests

packages/pinball_theme/test/src/themes/android_theme_test.dart

@@ -35,5 +35,12 @@ void main() {
     test('icon asset is correct', () {
       expect(AndroidTheme().icon, equals(Assets.images.android.icon));
     });
+
+    test('leaderboard icon asset is correct', () {
+      expect(
+        AndroidTheme().leaderboardIcon,
+        equals(Assets.images.android.leaderboardIcon),
+      );
+    });
   });
 }

packages/pinball_theme/test/src/themes/dash_theme_test.dart

@@ -35,5 +35,12 @@ void main() {
     test('icon asset is correct', () {
       expect(DashTheme().icon, equals(Assets.images.dash.icon));
     });
+
+    test('leaderboard icon asset is correct', () {
+      expect(
+        DashTheme().leaderboardIcon,
+        equals(Assets.images.dash.leaderboardIcon),
+      );
+    });
   });
 }

packages/pinball_theme/test/src/themes/dino_theme_test.dart

@@ -35,5 +35,12 @@ void main() {
     test('icon asset is correct', () {
       expect(DinoTheme().icon, equals(Assets.images.dino.icon));
     });
+
+    test('leaderboard icon asset is correct', () {
+      expect(
+        DinoTheme().leaderboardIcon,
+        equals(Assets.images.dino.leaderboardIcon),
+      );
+    });
   });
 }

packages/pinball_theme/test/src/themes/sparky_theme_test.dart

@@ -35,5 +35,12 @@ void main() {
     test('icon asset is correct', () {
       expect(SparkyTheme().icon, equals(Assets.images.sparky.icon));
     });
+
+    test('leaderboard icon asset is correct', () {
+      expect(
+        SparkyTheme().leaderboardIcon,
+        equals(Assets.images.sparky.leaderboardIcon),
+      );
+    });
   });
 }