rust: Add default functions for Facade

Bug: 200174377
Test: build floss
Tag: #floss
Change-Id: Ie9c23f71ff473a881e1e3d56eb495f0ebdc7b09a
diff --git a/build.py b/build.py
index fb209ef..8613315 100755
--- a/build.py
+++ b/build.py
@@ -160,7 +160,7 @@
       """
         rust_flags = [
             '-L',
-            '{}/out/Default/'.format(self.output_dir),
+            '{}/out/Default'.format(self.output_dir),
             '-C',
             'link-arg=-Wl,--allow-multiple-definition',
         ]