Steps to Reproduce

1. Select flutter channel beta
2. Add datepicker (doesn't matter if you add locale: to showDatePicker() or not)
3. Set phone to German (or a region with a different date format than US)
4. Run appliction, click on the pen to manually edit date
5. Edit one number

Expected results:
-> Locale is in my language + I can edit and save a date

Actual results:

1. The language is always English (while the Cancel and OK buttons are localized)
2. The date is auto-formatted to US format
3. When I type a dot, it enters a slash instead (German format: 24.4.2020 - we use dots)
4. It says Invalid format (to it's own correction - so it is actually expecting the German format)
   -> I can't save any date

If I choose English in phone settings, all works - because having '/' in a date is expected.
This happens in Xcode simulator as well as in the builds made by Codemagic.