fix(测试跟踪): 自定义字段值为空对象或空数组字符时解析有误

--bug=1024909 --user=宋昌昌 【测试跟踪】github#23178，自定义字段文本框输入{}会自动变为[object Object] https://www.tapd.cn/55049933/s/1356477

framework/sdk-parent/frontend/src/utils/custom_field.js

@@ -197,8 +197,8 @@ export function sortCustomFields(customFields) {
   let total = 0; //定义total用于控制循环结束
   for (let i = 0; total < customFields.length; total++) {
     if (
-      typeof customFields[i].defaultValue === "string" ||
-      customFields[i].defaultValue instanceof String
+      (typeof customFields[i].defaultValue === "string" ||
+      customFields[i].defaultValue instanceof String) && customFields[i].defaultValue !== '{}' && customFields[i].defaultValue !== '[]'
     ) {
       try {
         customFields[i].defaultValue = JSON.parse(customFields[i].defaultValue);