Fixing the accessibility CTS tests.

1. We are now requiring an accessibilitiy service to request
   a special premission in order to be considered by the
   system as an accessibility service. The delegating service
   did not require this permission, thus it was not enabled.

2. We decided that the input and accessibility focus will no
   longer try to sync - removed and update the relevant tests.

3. Manipulating accessibility focus now requires explore by
   touch mode - updated the tests drivers to poke the
   corresponding setting.

Change-Id: Ica617fa29208104086cc4155ac838cad086f6539