fixup! fix(material/datepicker): deprecate constructor injection in NativeDateAdapter

Author: mmalerba

tools/public_api_guard/material/core.md

@@ -418,7 +418,8 @@ export function mixinTabIndex<T extends _AbstractConstructor<CanDisable>>(base:
 
 // @public
 export class NativeDateAdapter extends DateAdapter<Date> {
-    constructor(matDateLocale: string,
+    constructor(
+    matDateLocale?: string,
     _platform?: Platform);
     // (undocumented)
     addCalendarDays(date: Date, days: number): Date;