[improvement] make props less magic (#3775)

src/mixins/checkbox.js

@@ -11,8 +11,8 @@ export const CheckboxMixin = ({ parent, bem, role }) => ({
   props: {
     name: null,
     value: null,
-    iconSize: [String, Number],
     disabled: Boolean,
+    iconSize: [Number, String],
     checkedColor: String,
     labelPosition: String,
     labelDisabled: Boolean,

src/mixins/popup/index.js

@@ -29,7 +29,7 @@ export const PopupMixin = {
     // whether to close popup when click overlay
     closeOnClickOverlay: Boolean,
     // z-index
-    zIndex: [String, Number],
+    zIndex: [Number, String],
     // prevent body scroll
     lockScroll: {
       type: Boolean,