Touch exploration state set to clients asynchronously and depended on talking...

Touch exploration state set to clients asynchronously and depended on talking service being enabled.

1. Upon registration of an accessibility client the latter received only
   the accessiiblity state and waiting for the touch exploration state
   to be sent by the system in async manner. This led the very first
   check of touch exploration state is checked a wrong value to be reported.
   Now a state of the accessibility layer is returned to the client
   upon registration.

2. Removing the dependency on talking accessibility service to be enabled
   for getting into touch exploration mode. What if the user wants to use
   an accessibility service that shows a dialog with the text of the touched
   view?

bug:5051546

Change-Id: Ib377babb3f560929ee73bd3d8b0d277341ba23f7