Switch the mac back to toybox xargs.

Test: make sdk
Change-Id: I29a6b0404e248553ecfdfdeb263aa9cd0d2fdb3e
diff --git a/ui/build/paths/config.go b/ui/build/paths/config.go
index f347a11..90ff706 100644
--- a/ui/build/paths/config.go
+++ b/ui/build/paths/config.go
@@ -119,9 +119,6 @@
 	"pgrep": LinuxOnlyPrebuilt,
 	"pkill": LinuxOnlyPrebuilt,
 	"ps":    LinuxOnlyPrebuilt,
-
-	// The toybox xargs is currently breaking the mac build.
-	"xargs": LinuxOnlyPrebuilt,
 }
 
 func init() {