Bug report

When a user navigates the DatePicker’s calendar using arrow keys, the component updates aria-activedescendant in the wrong order; it removes the id reference from the current cell before assigning it to the new cell. This creates a brief window in which aria-activedescendant points to an id that doesn't exist in the DOM.

Reproduction of the problem

(bug report only)
1. Run this example: https://blazorrepl.telerik.com/GgEKuoPQ289mGAyo13

Inspect the selected date in the calendar, select "break on attribute modification" for the td element of the selected date and the next td element. Navigate with "Right Arrow" key from the selected to the next date.

Current behavior

(optional)
The id of the selected date's td element is removed, but the DatePicker input’s aria-activedescendant attribute still has this id as value. Then the newly focused cell gets an id and it is set to the aria-activedescendant. 

Expected/desired behavior

The element referenced by aria-activedescendant must be in the DOM (https://www.w3.org/TR/wai-aria-1.2/#aria-activedescendant)

Environment

• Kendo/Telerik version: 14.0.0
• Browser: [all ]