Fix padding/margin for widgets in widgetpicker

Fix: 287079143
Test: Verify that the there's enough margin in between widgets and their container in widget picker
Change-Id: I6c8cbf075541d6db734fbbc5c0e2386b41c7edac
diff --git a/res/layout/widget_cell.xml b/res/layout/widget_cell.xml
index 55dd1de..9868e20 100644
--- a/res/layout/widget_cell.xml
+++ b/res/layout/widget_cell.xml
@@ -19,6 +19,7 @@
     android:layout_height="wrap_content"
     android:paddingHorizontal="@dimen/widget_cell_horizontal_padding"
     android:paddingVertical="@dimen/widget_cell_vertical_padding"
+    android:layout_marginHorizontal="@dimen/widget_cell_horizontal_padding"
     android:layout_weight="1"
     android:orientation="vertical"
     android:focusable="true"