code: @Override
      public void onClickDenyButton() {
          Toast.makeText(this, "You must confirm to activate SPF", Toast.LENGTH_SHORT).show();
          Log.d(TAG, "User clicked on DenyButton in Permission Disclaimer Dialog Fragment");
          finish();
      }
docs: Method defined in
  {@link it.polimi.spf.app.permissiondisclaimer.PermissionDisclaimerDialogFragment.PermissionDisclaimerListener}
  and called by
  {@link it.polimi.spf.app.permissiondisclaimer.PermissionDisclaimerDialogFragment}