Ignore focus event for digits field

On app launch digits field may have a focus, and the focus event
makes tts speak both the app name and the type of the View in a row
"phone, edit box"). This change suppresses the second part and let
tts speak just the app name on launch ("phone").

Bug: 5275935
Change-Id: Ideb62b01104a1701c71ca7af0d6fa05d8cc39657