Enable test assertions when running run_on_app

Change-Id: I4f942d1cbfb798f6b2e0219f7aac2429d04391af
diff --git a/tools/run_on_app.py b/tools/run_on_app.py
index cdceb6b..8667a9e 100755
--- a/tools/run_on_app.py
+++ b/tools/run_on_app.py
@@ -533,6 +533,9 @@
   if options.print_times:
     extra_args.append('-Dcom.android.tools.r8.printtimes=1')
 
+  if not options.no_debug:
+    extra_args.append('-Dcom.android.tools.r8.enableTestAssertions=1')
+
   outdir = options.out
   (version_id, data) = get_version_and_data(options)