[Fleet] Fix packages being upgraded accidentally after adding to policy

[jen-huang]

Summary

Fixes #99649. This PR fixes a bug where packages would be upgraded on adding it to an agent policy. How to test:

1. Force install an older version of a package, i.e. for apache

POST <host>/api/fleet/epm/packages/apache-0.3.0
{
  "force": true
}

2. Add apache to any agent policy
3. Go to Integrations > Apache, observe that the version installed should remain as 0.3.0 and it was not accidentally upgraded to the latest version

[elasticmachine]

Pinging @elastic/fleet (Team:Fleet)

[kibanamachine]

💚 Build Succeeded

• continuous-integration/kibana-ci/pull-request
• Commit: eb0f8d0
• Storybooks Preview

Metrics [docs]

✅ unchanged

To update your PR or re-run it, just comment with:
@elasticmachine merge upstream

cc @jen-huang

[nchaulet]

🚀

[kibanamachine]

💚 Backport successful

Status	Branch	Result
✅	7.13
✅	7.x

The backport PRs will be merged automatically after passing CI.

[dikshachauhan-qasource]

Hi @jen-huang

We have validated this PR on 7.14 Snapshot build and found it available there.

-We are now able to add lower version packages to Policy.

• Package version is not upgraded to latest version when added under any policy.

Screenshot:

Thanks
QAS