Fix missing field access in run_on_as_app.py

Change-Id: If155f4e947633baccda2e706037cb3087134b610
diff --git a/tools/run_on_as_app.py b/tools/run_on_as_app.py
index 0c30532..b9e17ab 100755
--- a/tools/run_on_as_app.py
+++ b/tools/run_on_as_app.py
@@ -555,7 +555,7 @@
   # Add settings.gradle file if it is not present to prevent gradle from finding
   # the settings.gradle file in the r8 root when apps are placed under
   # $R8/build.
-  as_utils.add_settings_gradle(checkout_dir, app)
+  as_utils.add_settings_gradle(checkout_dir, app.name)
 
   # Add 'r8.jar' to top-level build.gradle.
   as_utils.add_r8_dependency(checkout_dir, temp_dir, IsMinifiedR8(shrinker))