[Improvement][UI] Image pull policy in the K8S task provides default values (#14650)

Signed-off-by: Gallardot <gallardot@apache.org>
Co-authored-by: Aaron Wang <wangweirao16@gmail.com>

dolphinscheduler-ui/src/views/projects/task/components/node/fields/use-k8s.ts

@@ -76,7 +76,8 @@ export function useK8s(model: { [field: string]: any }): IJsonItem[] {
         trigger: ['input', 'blur'],
         required: true,
         message: t('project.node.image_pull_policy_tips')
-      }
+      },
+      value: 'IfNotPresent'
     },
     {
       type: 'input',