Fix flag for java vm in run on app

Change-Id: I41fe4670587390d9e28030a33c3b2a70572f20c0
diff --git a/tools/run_on_app.py b/tools/run_on_app.py
index 76fc59b..c5e0f7d 100755
--- a/tools/run_on_app.py
+++ b/tools/run_on_app.py
@@ -173,7 +173,7 @@
   app_provided_pg_conf = False;
   extra_args = []
   # todo(121018500): remove when memory is under control
-  extra_args.append('-Xmx8GB')
+  extra_args.append('-Xmx8G')
   if options.golem:
     golem.link_third_party()
     options.out = os.getcwd()