[SetupWizard] Fix shadow for ListView

Fix the shadow cast by the illustration for ListViews on phone
portrait by not clipping the header view.

Bug: 20731843
Change-Id: I4d6cc759191278698609401b0d4a764bd9e3d1a0

library/main/res/layout/suw_list_header.xml

@@ -19,6 +19,7 @@
     xmlns:tools="http://schemas.android.com/tools"
     android:layout_width="match_parent"
     android:layout_height="wrap_content"
+    android:clipToPadding="false"
     android:orientation="vertical"
     android:tag="stickyContainer">
 

library/main/res/layout/suw_list_template_header.xml

@@ -26,6 +26,7 @@
         android:layout_width="match_parent"
         android:layout_height="0dp"
         android:layout_weight="1"
+        android:clipChildren="false"
         app:suwHeader="@layout/suw_list_header" />
 
     <com.android.setupwizardlib.view.NavigationBar