Poll for isTouchExplorationEnabled

This test could possibly fail if isTouchExplorationEnabled is false and
some setState message has not been processed by
AccessibilityManagerTest. Maybe it's a thread visibility issue though
and the test doesn't see the update.

Bug 6537582

Change-Id: I0c691813a0d5e2ad1312bcb04ded2650ae0c0019
3 files changed