add sleep to ensure proxy starts before use

Author: glasnt

cloud-sql/mysql/mysql/test/proxy-setup.sh

@@ -17,3 +17,4 @@
 curl -o cloud-sql-proxy https://storage.googleapis.com/cloud-sql-connectors/cloud-sql-proxy/v2.15.1/cloud-sql-proxy.linux.amd64
 chmod +x cloud-sql-proxy
 ./cloud-sql-proxy $CLOUD_SQL_CONNECTION_NAME &
+sleep 10