Switch to toybox cp(1).

Test: treehugger
Change-Id: I91eddd95abc03f76d4da7fdc1e70c5cf314e6127
diff --git a/ui/build/paths/config.go b/ui/build/paths/config.go
index 1bcbec1..604bf90 100644
--- a/ui/build/paths/config.go
+++ b/ui/build/paths/config.go
@@ -78,7 +78,6 @@
 	"bash":      Allowed,
 	"bc":        Allowed,
 	"bzip2":     Allowed,
-	"cp":        Allowed,
 	"date":      Allowed,
 	"dd":        Allowed,
 	"diff":      Allowed,
@@ -156,6 +155,7 @@
 	"chmod":    Toybox,
 	"cmp":      Toybox,
 	"comm":     Toybox,
+	"cp":       Toybox,
 	"cut":      Toybox,
 	"dirname":  Toybox,
 	"env":      Toybox,