Make gutter between folders and docs smaller.

And shrink margin around grid by 1.

Change-Id: I36ebc23b8d7d4748f846f582614ba7835927c1d4
diff --git a/res/values/dimens.xml b/res/values/dimens.xml
index b07ce97..f8e7932 100644
--- a/res/values/dimens.xml
+++ b/res/values/dimens.xml
@@ -28,7 +28,8 @@
     <dimen name="grid_height">176dp</dimen>
     <dimen name="grid_item_width">152dp</dimen>
     <dimen name="grid_item_height">176dp</dimen>
-    <dimen name="grid_item_margin">7dp</dimen>
+    <dimen name="grid_section_separator_height">0dp</dimen>
+    <dimen name="grid_item_margin">6dp</dimen>
     <dimen name="grid_padding_horiz">4dp</dimen>
     <dimen name="grid_padding_vert">4dp</dimen>
     <dimen name="list_item_height">72dp</dimen>