Fix: Dropdown.Button not fully disabled (#9013)

* fix(Dropdown): dropdown won't be fully disabled

* test(Dropdown): check  props pass to Dropdown

components/dropdown/__tests__/__snapshots__/demo.test.js.snap

@@ -58,6 +58,7 @@ exports[`renders ./components/dropdown/demo/dropdown-button.md correctly 1`] = `
     </button>
     <button
       class="ant-btn ant-dropdown-trigger ant-btn-default"
+      disabled=""
       type="button"
     >
       <i

components/dropdown/__tests__/dropdown-button.test.js

@@ -14,6 +14,7 @@ describe('DropdownButton', () => {
           <Menu.Item>foo</Menu.Item>
         </Menu>
       ),
+      disabled: false,
       trigger: ['hover'],
       visible: true,
       onVisibleChange: () => {},

components/dropdown/dropdown-button.tsx

@@ -31,6 +31,7 @@ export default class DropdownButton extends React.Component<DropdownButtonProps,
     const dropdownProps = {
       align,
       overlay,
+      disabled,
       trigger: disabled ? [] : trigger,
       onVisibleChange,
       placement,
@@ -53,7 +54,7 @@ export default class DropdownButton extends React.Component<DropdownButtonProps,
           {children}
         </Button>
         <Dropdown {...dropdownProps}>
-          <Button type={type} disabled={disabled}>
+          <Button type={type}>
             <Icon type="down" />
           </Button>
         </Dropdown>