UI test automation not working.

1. The internal service instance created by AccessibilityManagerService
   was getting the looper of the current thread when created. This works
   for real accessibility services but since UI automation service is
   registered via an IPC the binder thread has no looper. Now we explicitly
   get the correct looper.

bug:6535435

Change-Id: I63a2ada1b65c4b3c71c3d1e6deb3dfdeb7a3d6d6