Do not handle touches next to shelf Take #2

NSSL would return true for all touches below the last notification,
and to the right of the shelf. This is essentially empty space.
The reason for this is the SwipeHelper is always returning true,
since it is looking at the full width of the NotificationShelf. By
using getActualWidth() instead, the touches are more accurately
handled.

This fixes an issue where the shelf is vertically overlapping
the unlock icon, and taking touches from it.

Fixes: 358424256
Test: atest NotificationSwipeHelperTest
Test: manual - horizontal swipe notifications
Test: manual - vertically swipe notifications
Test: manual - all touch interactions with notifs
Test: manual - tap on shelf to expand shade
Test: manual - face auth without bypass, add notifications next
to unlock icon, use unlock
Flag: com.android.systemui.ignore_touches_next_to_notification_shelf
(cherry picked from https://googleplex-android-review.googlesource.com/q/commit:bff27edb33096142a76fed89dbf0cc4f91df969c)
(cherry picked from https://googleplex-android-review.googlesource.com/q/commit:4ed24bd6ad4933eba9e4e361bbfde04afa42c211)
Merged-In: Idf22d6e72e7d618ed98e869142b5cc5dc785985e
Change-Id: Idf22d6e72e7d618ed98e869142b5cc5dc785985e