refactor(接口测试): 接口定义导入 har 文件报错修复

--bug=1009828 --user=周骏弘 【接口测试】github#9732，导入har包报错 https://www.tapd.cn/55049933/s/1099430

backend/src/main/java/io/metersphere/api/dto/definition/parse/HarParser.java

@@ -243,9 +243,11 @@ public class HarParser extends HarAbstractParser {
             return;
         }
         String contentType = content.mimeType;
+        if(body != null){
             body.setType(getBodyType(contentType));
             body.setRaw(content.text);
         }
+    }
 
     private String parseXmlBody(String xmlString) {
         JSONObject object = JSONObject.parseObject(getDefaultStringValue(xmlString));

backend/src/main/java/io/metersphere/api/dto/scenario/Body.java

@@ -37,10 +37,13 @@ public class Body {
 
     public boolean isValid() {
         if (this.isKV()) {
+            if(kvs != null){
                 return kvs.stream().anyMatch(KeyValue::isValid);
+            }
         } else {
             return StringUtils.isNotBlank(raw);
         }
+        return false;
     }
 
     public boolean isKV() {