Add a timeout for lava-test-shell action in the generated job.
diff --git a/lava-submit.py b/lava-submit.py
index d17b9f2..e2f22cd 100755
--- a/lava-submit.py
+++ b/lava-submit.py
@@ -177,6 +177,7 @@
         actions.append({
             "command": "lava_test_shell",
             "parameters": {
+                    "timeout": 18000,
                     "testdef_repos": test_list
             }
         })