try different random suffix generator

Author: glasnt

eventarc/pubsub/test/runner.sh

@@ -23,7 +23,7 @@ requireEnv SERVICE_NAME
 requireEnv CONTAINER_IMAGE
 
 # TODO: update if random suffix is supported in ci-setup.json
-RANDOM_SUFFIX=$(tr -dc A-Za-z0-9 </dev/urandom | head -c 13)
+RANDOM_SUFFIX=$RANDOM
 export SERVICE_NAME="${SERVICE_NAME}-${RANDOM_SUFFIX}"
 export CONTAINER_IMAGE="${CONTAINER_IMAGE}:${RANDOM_SUFFIX}"