ansible-inventories/arocom#3114 Update db isolation settings

templates/d8_settings.php.jinja2

@@ -14,7 +14,7 @@ $databases = array (
       'charset' => 'utf8mb4',
       'collation' => 'utf8mb4_general_ci',
       'init_commands' => [
-        'tx_level' => "SET TRANSACTION ISOLATION LEVEL READ COMMITTED;",
+        'isolation_level' => 'SET SESSION TRANSACTION ISOLATION LEVEL READ COMMITTED',
       ],
     ),
   ),
@@ -32,7 +32,7 @@ $databases = array (
       'charset' => 'utf8mb4',
       'collation' => 'utf8mb4_general_ci',
       'init_commands' => [
-        'tx_level' => "SET TRANSACTION ISOLATION LEVEL READ COMMITTED;",
+        'isolation_level' => 'SET SESSION TRANSACTION ISOLATION LEVEL READ COMMITTED',
       ],
     ),
   ),