added DB_DRIVER as an env var

recipes/doctrine/doctrine-bundle/etc/packages/doctrine.yaml

@@ -1,6 +1,6 @@
 doctrine:
     dbal:
-        driver: pdo_mysql
+        driver: "%env(DB_DRIVER)%"
         host: "%env(DB_HOST)%"
         port: "%env(DB_PORT)%"
         dbname: "%env(DB_NAME)%"

recipes/doctrine/doctrine-bundle/manifest.json

@@ -7,6 +7,7 @@
         "src/": "%SRC_DIR%/"
     },
     "env": {
+        "DB_DRIVER": "pdo_mysql",
         "DB_HOST": "127.0.0.1",
         "DB_PORT": "",
         "DB_NAME": "symfony",