cli: config: update default template for multi-line overridden values

cli/src/config/templates.toml

@@ -15,13 +15,9 @@ if(remote,
 commit_summary = 'format_commit_summary_with_refs(self, branches)'
 
 config_list = '''
-label(if(overridden, "overridden"),
-  concat(
-    if(overridden, "# "),
-    name,
-    "=",
-    value,
-  ),
+if(overridden,
+  label("overridden", indent("# ", name ++ "=" ++ value)),
+  name ++ "=" ++ value,
 ) ++ "\n"
 '''
 

cli/tests/test_config_command.rs

@@ -156,6 +156,24 @@ bar
     bar
     """
     "###);
+
+    let stdout = test_env.jj_cmd_success(
+        test_env.env_root(),
+        &[
+            "config",
+            "list",
+            "multiline",
+            "--include-overridden",
+            "--config-toml=multiline='single'",
+        ],
+    );
+    insta::assert_snapshot!(stdout, @r###"
+    # multiline="""
+    # foo
+    # bar
+    # """
+    multiline="single"
+    "###);
 }
 
 #[test]