Remove elevation from the full widgets picker container

Test: Open the full widgets picker and observe no shadow added to the
      rounded corners.
Bug: 189808029
Change-Id: I539f6ebc0310cd4a037cd5eab6db4ee22b579195
diff --git a/res/layout/widgets_full_sheet.xml b/res/layout/widgets_full_sheet.xml
index a01aa2c..dca3e79 100644
--- a/res/layout/widgets_full_sheet.xml
+++ b/res/layout/widgets_full_sheet.xml
@@ -25,8 +25,7 @@
         android:id="@+id/container"
         android:layout_width="match_parent"
         android:layout_height="match_parent"
-        android:background="?android:attr/colorBackground"
-        android:elevation="4dp">
+        android:background="?android:attr/colorBackground">
 
         <TextView
             android:id="@+id/no_widgets_text"