Unexpected context data lost when a portal component was unmounted

[Macrox]

Describe the bug

ConfigProvider.getContext() will losing its cached context data after a portal component (e.g.: Dialog.show()) was unmounted.

Version of the Next Components

^1.9.15

Reproduce URL

https://codepen.io/anon/pen/vQgmbP?&editors=0010

To Reproduce

1. Use <ConfigProvider> to wrap the app.
2. Set locale prop on <ConfigProvider> with { Dialog: { ok: 'OK', cancel: 'Cancel' } }
3. Call Dialog.confirm or the other method which do create a portal modal
4. Close the modal
5. Call Dialog.confirm again

Expected behavior

The text of the modal's button always be OK and Cancel, but it'll be 确定 and 取消 except first mounting.