[Fleet]: Upgrade package policy button not greyed out on Upgraded integration under Integration>Policies page.

[amolnater-qasource]

Kibana version: 7.15.0 Snapshot Kibana Cloud environment

Host OS and Browser version: All, All

Build details:

Build: 43944
Commit: 951240e085cc4465167ab4d6bcdf6f267446a874

Preconditions:

1. 7.15.0 Snapshot Kibana Cloud environment should be available.
2. Lower version Nginx integration should be available, say 0.2.4.

Steps to reproduce:

1. Login to Kibana environment.
2. Add multiple Lower version Nginx integrations to Default Policy.
3. Observe v0.2.4 version Nginx added to Default Policy.
4. Upgrade Nginx integration from Settings, i.e, v0.7.0.
5. After successful upgrade navigate to Nginx Integration>Policies.
6. Click Upgrade button for lower version Nginx integration and click Save Integration.
7. User is navigated back to Policies tab and click "..." under Action for newly upgraded policy.
8. Observe Upgrade package policy button is not greyed out and on clicking navigates user to Upgrade Integration page.

Expected Result:
Upgrade package policy button should be greyed out on Upgraded integration under Integration>Policies page.

What's working:
Upgrade package policy button is greyed out on Upgraded integration under Policies>Policy details page.

Screenshot:

[elasticmachine]

Pinging @elastic/fleet (Team:Fleet)

[jen-huang]

@hop-dev Assigning to you while Kyle is on PTO as you have worked in this area :)

[hop-dev]

@jen-huang Should the fix for this be included in 7.15?

[jen-huang]

@hop-dev Yes please :) Added the tag to your PR. Thanks!