Move Note Shortcut from Settings to SystemUI

* Moves the Note Shortcut showed on Widget Picker back to SystemUI.
* By placing everything inside SystemUI, we do not need to give special
 privileges to System apps to by-pass any shortcut checks. That was
 required due to multi-process communication.

Test: atest SystemUITests:NoteTaskControllerTest
Flag: not needed
Fixes: b/280431176
Change-Id: I8239e31a3767959f8ad9beeaefe6528f7fedae99