fix(Rating): fix grade background, close #4734 (#4735)

Co-authored-by: chenkeyao.chenkeya <[email protected]>

components/rating/main.scss

@@ -111,7 +111,7 @@
             height: 4px;
             transform: rotate(45deg);
             border: 1px solid $color-fill1-4;
-            background: $color-white;
+            background: $rating-grade-background;
             border-bottom-color: transparent;
             border-right-color: transparent;
             top: -3px;