Made the qs scroll view not important for accessibility

It was showing up as an unlabeled element, but can't usually
be scrolled anyway. And when it's scrolled it can still be performed
using talkback.

Fixes: 160329869
Test: enable talkback, drag down notification panel
Change-Id: Iaf4785213c58cb9efeb19aff4c164f78cdacfdab

packages/SystemUI/res/layout/qs_panel.xml

@@ -53,6 +53,7 @@
         android:layout_width="match_parent"
         android:layout_height="wrap_content"
         android:elevation="4dp"
+        android:importantForAccessibility="no"
         android:layout_weight="1">
         <com.android.systemui.qs.QSPanel
             android:id="@+id/quick_settings_panel"