Keyboard a11y - ESC and ALT-UP keys don't close autocomplete

[DaveBest99]

Bug, feature request, or proposal:

Bug: Keyboard user cannot close the list box with Escape or alt+up_arrow keys.

What is the expected behavior?

For an auto-complete that has text in the text box that was both typed by the user and auto-completed by highlighting a choice using the keyboard, pressing escape or alt+up_arrow closes the drop-down list and should clear the text box. Pressing alt+down_arrow should open the list box and allow the user to press up/down arrow keys in the list box and type in the Edit box.

What is the current behavior?

Currently the keyboard user cannot close the list box without selecting an item.

What is the use-case or motivation for changing an existing behavior?

To allow keyboard users a good interactive experience.

Is there anything else we should know?

Pressing the Escape key appears to do nothing. Pressing the Alt+up_arrow JAWS says "close list box", but nothing actually happens as the user can still press up/down arrow keys through the list box. The Edit box is not cleared. Pressing alt+down_arrow has the same effect as pressing down arrow. The alt+up_arrow should collapse the list box and alt+down_arrow should expand the list box.

[kara]

Related: #3416

[crisbeto]

Closing both through escape and alt+up arrow is supported now.

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