Center drop target icons in landscape mode.

Spec: https://docs.google.com/presentation/d/1UxdDh8EFhPbdRWRwzjbpgL-j02ew4Ew3eG3XBCeoYdo/edit#slide=id.vXfwHn8

Test: manual
Bug: 187376586
Change-Id: I2025ba75061a5ca3a004dfef2b33cdbcc17a1408
diff --git a/res/values/dimens.xml b/res/values/dimens.xml
index 12f50e5..d0fc87b 100644
--- a/res/values/dimens.xml
+++ b/res/values/dimens.xml
@@ -48,7 +48,7 @@
     <dimen name="workspace_page_indicator_overlap_workspace">0dp</dimen>
 
 <!-- Drop target bar -->
-    <dimen name="dynamic_grid_drop_target_size">48dp</dimen>
+    <dimen name="dynamic_grid_drop_target_size">52dp</dimen>
     <dimen name="drop_target_vertical_gap">20dp</dimen>
 
 <!-- App Widget resize frame -->