Customize lock screen button access via A11y tools

The ability to long-press on lockscreen was not available by Talkback or
Switch Access.

When the user triggers the "customize lock screen" from an A11y action
within the switch access popup or other tools, we should bypass the menu
from showing up and displaying, and instead go straight into the
auth->wallpaper picker flow.

Fixes: 318039541
Fixes: 318036479
Test: atest KeyguardTouchHandlingInteractorTest
Test: manual - activate Talkback on foldable and udfps devices
Test: manual - activate Switch Access on foldable and udfps devices
Flag: EXEMPT bugfix
Change-Id: I3ebfae00c21b80a35c6d642e8aaff0ab63494311