Fix talkback not automatically announcing in Gesture Nav Tutorial

This change explicitly sets the Talkback attributes to allow for
automatically scrolling to the subtitle in the gesture navigation
tutorial. Previously, you would have to tap the subtitle for it to be
announced.

Fix: 386884587
Test: Run the tutorial with talkback enabled and observe talkback announcing the
title and subtitle of the current gesture
Flag: EXEMPT bugfix

Change-Id: I6ca2c1654f9e481165e2135e9afd72fa178f8184