Don't fade out active page outline during drag-and-drop

=> Keep page backgrounds stable and only slightly modify the alpha + add stroke for active page
=> Don't shrink cell outlines to be too small (issue in hotseat on some devices)
=> Reduce cell radius to 22dp

Bug: 185163323
Test: manual

Change-Id: Ic17999f5672a3355dceeb25af923f02e960389d9
diff --git a/res/values/dimens.xml b/res/values/dimens.xml
index 600a550..0a6cce9 100644
--- a/res/values/dimens.xml
+++ b/res/values/dimens.xml
@@ -293,7 +293,7 @@
     <dimen name="overview_task_margin">0dp</dimen>
 
 <!-- Workspace grid visualization parameters -->
-    <dimen name="grid_visualization_rounding_radius">28dp</dimen>
+    <dimen name="grid_visualization_rounding_radius">22dp</dimen>
     <dimen name="grid_visualization_cell_spacing">6dp</dimen>
 
 </resources>