bug(Datepicker): locale with MomentDateAdapter

[vdelplanque]

Is this a regression?

• Yes, this behavior used to work in the previous version

The previous version in which this bug was not present was

19.2.19

Description

The MomentDateAdapter doesn't take the local in account anymore.

Reproduction

StackBlitz link:
Steps to reproduce:

1. In the documentation of the v19, the Datepicker correctly switches to Japanese to French: https://v19.material.angular.dev/components/datepicker/overview#setting-the-locale-code
2. In the v20 documentation, the dateformat, months, days, first day of week, etc stays in US: https://material.angular.dev/components/datepicker/overview#setting-the-locale-code

Expected Behavior

The Datepicker should switch to Japanese to French locale

Actual Behavior

The Datepicker keeps displaying US format

Environment

• Angular:
• CDK/Material:
• Browser(s):
• Operating System (e.g. Windows, macOS, Ubuntu):

Hint

When I build my app with "builder": "@angular-devkit/build-angular:browser" instead of "builder": "@angular/build:application" it works, even in version 20