fix: calendar-body cell value display fixed

Author: matheo

src/datepicker/calendar-body.html

@@ -44,6 +44,6 @@
          [class.mat-calendar-body-active]="activeValue === item.value"
          [class.mat-calendar-body-today]="todayValue === item.value">
     </div>
-    <span class="mat-calendar-body-cell-content"> item.displayValue }}</span>
+    <span class="mat-calendar-body-cell-content">{{ item.displayValue }}</span>
   </td>
 </tr>