Fixes Talkback autoscroll for SFPS enrollment ScrollView

Adds importantForAccessibility attribute to ScrollView in setup wizard layout. This enables Talkback to autoscroll when focusing on items at the edge of a container.

Test: (manual) Turn on talkback, navigate to SFPS enrollment edu screen. Swipe through ScrollView elements and observe autoscroll when focus is on elements at the edge of the View.
Fixes: 244595576
Change-Id: Iccc6125ac8f0993a7d8908f6c54e7307905b7cd7