Move rmdir(1) to toybox.

Test: treehugger
Change-Id: Ibb43f09c0cfcda631025ef0fea4730519a3b6fe6
diff --git a/ui/build/paths/config.go b/ui/build/paths/config.go
index 5e68db8..5f28b38 100644
--- a/ui/build/paths/config.go
+++ b/ui/build/paths/config.go
@@ -125,7 +125,6 @@
 	"readlink":  Allowed,
 	"realpath":  Allowed,
 	"rm":        Allowed,
-	"rmdir":     Allowed,
 	"rsync":     Allowed,
 	"sed":       Allowed,
 	"setsid":    Allowed,
@@ -172,6 +171,7 @@
 	"id":     Toybox,
 	"od":     Toybox,
 	"pwd":    Toybox,
+	"rmdir":  Toybox,
 	"sleep":  Toybox,
 	"tail":   Toybox,
 	"true":   Toybox,