We need to be able to initiate touch exploration even if there are no pointers on the screen in order to reliably cover the case where a user just taps the screen. The user expects to hear if they have tapped on anything. Bug: 223673301 Test: manual. Tap on the screen and confirm that talkback reads the item in that position. Change-Id: Id96fa8bd7f000ea153f45024e06915a43ca80826