[Fleet] skip output validation when create/update package policy (#216438)

## Summary

Closes https://github.com/elastic/kibana/issues/198107

Skip output validation on bump agent policy, it's unnecessary after the
package policy create/update logic already does the validation with the
correct integration output.

To verify:
- Create an agent policy with a remote ES output as data output
- Add fleet server integration - expect error as the default remote ES
output can't be used with fleet server
- Change integration output to the ES output - expect creation
successful
- Edit fleet server integration (keep ES output) - expect update
successful

<img width="1685" alt="image"
src="https://github.com/user-attachments/assets/42a0365c-1f00-42b6-b685-7797e9c916de"
/>
<img width="1714" alt="image"
src="https://github.com/user-attachments/assets/af22cea1-d8b3-4d44-a24d-78dff49eeaaa"
/>
<img width="1699" alt="image"
src="https://github.com/user-attachments/assets/aafc7e5c-b9e6-47b8-9001-16e08cf06205"
/>
<img width="1704" alt="image"
src="https://github.com/user-attachments/assets/e6e7ef47-918a-423f-a54c-11836362d495"
/>
<img width="1712" alt="image"
src="https://github.com/user-attachments/assets/128ef119-2178-4971-9e0f-bb773c2f774a"
/>
<img width="1707" alt="image"
src="https://github.com/user-attachments/assets/cd49716d-aa38-42ff-9329-3d97f08f9e7e"
/>


### Checklist

- [ ] [Unit or functional
tests](https://www.elastic.co/guide/en/kibana/master/development-tests.html)
were updated or added to match the most common scenarios

x-pack/platform/plugins/shared/fleet/server/services/agent_policy.ts

@@ -913,13 +913,18 @@ class AgentPolicyService {
     soClient: SavedObjectsClientContract,
     esClient: ElasticsearchClient,
     id: string,
-    options?: { user?: AuthenticatedUser; removeProtection?: boolean; asyncDeploy?: boolean }
+    options?: {
+      user?: AuthenticatedUser;
+      removeProtection?: boolean;
+      asyncDeploy?: boolean;
+      skipValidation?: boolean;
+    }
   ): Promise<void> {
     return withSpan('bump_agent_policy_revision', async () => {
       await this._update(soClient, esClient, id, {}, options?.user, {
         bumpRevision: true,
         removeProtection: options?.removeProtection ?? false,
-        skipValidation: false,
+        skipValidation: options?.skipValidation ?? true,
         returnUpdatedPolicy: false,
         asyncDeploy: options?.asyncDeploy,
       });