Fix accessibility focus bug in statusbar

The notification_stack_scroller view of the new uber statusbar should
not be focusable for accessibility

Fixes bug 19296202

Change-Id: I1b3f43ee3c480c705044cb3d565c7c7f7019bcc3
diff --git a/packages/SystemUI/res/layout/status_bar_expanded.xml b/packages/SystemUI/res/layout/status_bar_expanded.xml
index f6d4be5..5c41436 100644
--- a/packages/SystemUI/res/layout/status_bar_expanded.xml
+++ b/packages/SystemUI/res/layout/status_bar_expanded.xml
@@ -97,7 +97,8 @@
             android:layout_width="@dimen/notification_panel_width"
             android:layout_height="match_parent"
             android:layout_gravity="@integer/notification_panel_layout_gravity"
-            android:layout_marginBottom="@dimen/close_handle_underlap" />
+            android:layout_marginBottom="@dimen/close_handle_underlap"
+            android:importantForAccessibility="no" />
 
         <ViewStub
             android:id="@+id/keyguard_user_switcher"