bug(mat-date-picker): the native date adapter can't detect first day of week from user locale

#### Reproduction

All material datepickers display weeks starting Sunday while I have Russia locale set up which demands Monday is the first day of week:

Yes, I know I can globally change starting day via DateAdapter but I need to datepickers to be users' locale compatible.

#### Expected Behavior
Monday is first day of week

#### Actual Behavior

Sunday is first day of week.

#### Environment

- Angular: 11.0.3
- CDK/Material: 11.2.4
- Browser(s): Firefox 89
- Operating System (e.g. Windows, macOS, Ubuntu): macOS 11.4

Start by reproducing the issue with Angular Material datepickers and a Russia locale, then inspect the native date adapter and its locale handling. Done means the datepicker displays Monday as the first day of the week for that locale while preserving the existing global DateAdapter override behavior.

Written by the indexing model from the issue text.