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

Author: sganov

services/java/com/android/server/accessibility/AccessibilityManagerService.java

@@ -1068,7 +1068,7 @@ class Service extends IAccessibilityServiceConnection.Stub
         /**
          * Handler for delayed event dispatch.
          */
-        public Handler mHandler = new Handler() {
+        public Handler mHandler = new Handler(mMainHandler.getLooper()) {
             @Override
             public void handleMessage(Message message) {
                 final int type = message.what;