Remove build/libs

Bug: 28001743
Change-Id: Id5bcc11a08b3677ee1caf5b564ef0f2fb65026da
diff --git a/root.bp b/root.bp
index 822e65b..2b72cfa 100644
--- a/root.bp
+++ b/root.bp
@@ -8,7 +8,6 @@
 optional_subdirs = [
     "bionic",
     "build/kati",
-    "build/libs/*",
     "build/tools/*",
     "dalvik",
     "external/*",