ENYO-1124: add more comment about accessibilityAlert
ENYO-1124: add more comment about accessibilityAlert

add more comment about accessibilityAlert

Enyo-DCO-1.1-Signed-off-by: Jaewon Jang <jaewon98.jang@lgepartner.com>

enyojs/enyo,enyojs/enyo,PKRoma/enyo,PKRoma/enyo