Move sed(1) to toybox.

Test: treehugger
Change-Id: I338cffd5de27af0a93d0f379d021da5ccb2e5721
diff --git a/ui/build/paths/config.go b/ui/build/paths/config.go
index 4dc62b8..d6f11b1 100644
--- a/ui/build/paths/config.go
+++ b/ui/build/paths/config.go
@@ -113,7 +113,6 @@
 	"realpath":  Allowed,
 	"rm":        Allowed,
 	"rsync":     Allowed,
-	"sed":       Allowed,
 	"sh":        Allowed,
 	"sha1sum":   Allowed,
 	"sha256sum": Allowed,
@@ -166,6 +165,7 @@
 	"paste":    Toybox,
 	"pwd":      Toybox,
 	"rmdir":    Toybox,
+	"sed":      Toybox,
 	"setsid":   Toybox,
 	"sleep":    Toybox,
 	"tail":     Toybox,