feat(Coupon): add @coupon-corner-checkbox-icon-color var (#8323)

src/coupon/Coupon.tsx

@@ -1,6 +1,5 @@
 import { computed, PropType, defineComponent } from 'vue';
 import { padZero, createNamespace } from '../utils';
-import { RED } from '../utils/constant';
 import { Checkbox } from '../checkbox';
 
 export type CouponInfo = {
@@ -101,11 +100,7 @@ export default defineComponent({
               <p class={bem('name')}>{coupon.name}</p>
               <p class={bem('valid')}>{validPeriod.value}</p>
               {!disabled && (
-                <Checkbox
-                  class={bem('corner')}
-                  modelValue={chosen}
-                  checkedColor={RED}
-                />
+                <Checkbox class={bem('corner')} modelValue={chosen} />
               )}
             </div>
           </div>

src/coupon/index.less

@@ -80,6 +80,11 @@
     top: 0;
     right: @padding-md;
     bottom: 0;
+
+    .van-checkbox__icon--checked .van-icon {
+      background-color: @coupon-corner-checkbox-icon-color;
+      border-color: @coupon-corner-checkbox-icon-color;
+    }
   }
 
   &__description {