Moving the scrim to draglayer

> This causes the scrim to animate with the content on first launch
> Also removing the logic to disable scrim based on state. That
logic was only executing onResume which could lead to an invalid state

Bug: 30972956
Bug: 30576826

Change-Id: Ia8386b303ce260f69e3b3b93041226f409301a01
diff --git a/res/layout-sw720dp/launcher.xml b/res/layout-sw720dp/launcher.xml
index 3a429c6..81d2e1b 100644
--- a/res/layout-sw720dp/launcher.xml
+++ b/res/layout-sw720dp/launcher.xml
@@ -28,6 +28,7 @@
         android:clipChildren="false"
         android:clipToPadding="false"
         android:importantForAccessibility="no"
+        android:background="@drawable/workspace_bg"
         android:layout_width="match_parent"
         android:layout_height="match_parent">