Support has been added for:
* Esc: Closes the dialog
* Tab: Ensures that tabbing keeps focus on the focusable elements
in the dialog. If no overlay is not present, the focus is
allowed to flow normally.
This should not happen but if NO focusable elements are found and
overlay is displayed, focus is locked on the overlay.
Also add description and other license information for uls.dialog
& uls.setlang files.
Bug: T63115
Change-Id: Ie3215d12d9c77f15597495e21610707b272eeee9
5ad4f74ea9