fix(material/datepicker): fix failing unit test in multiyear view (#24418)

Fix a failing unit test, which was referencing Jan 1, 2017 as the initial
date when it is actually Jan 3, 2017. This happened as a result of a bad
merge where #24384 changed the initial date to Jan 3, and #24401 added a
new test that assume the initial date was Jan 1.

Fixes CI failure

Author: zarend

src/material/datepicker/multi-year-view.spec.ts

@@ -241,7 +241,7 @@ describe('MatMultiYearView', () => {
           dispatchFakeEvent(year2017Cell, 'focus');
           fixture.detectChanges();
 
-          expect(calendarInstance.date).toEqual(new Date(2017, JAN, 1));
+          expect(calendarInstance.date).toEqual(new Date(2017, JAN, 3));
           expect(focusSpy).not.toHaveBeenCalled();
         });
       });