[Fleet]: Only 20 agents count is shown under Add agent flyout even if more than 20 agents are installed within 10 minutes of duration.

[amolnater-qasource]

Kibana version: 8.4 BC-2 Kibana cloud environment

Host OS and Browser version: All, All

Build details:

VERSION: 8.4.0
BUILD: 55166
COMMIT: 9e9e0d6a685cbc2858a85a357f93dcb76259fdee

Preconditions:

1. 8.4 BC2 Kibana cloud environment should be available.

Steps to reproduce:

1. Login to Kibana environment.
2. Install more than 20 agents with same policy within 10 minutes of duration.
3. Observe count under Add agent flyout doesn't increase 20 agents have been enrolled .

Expected Result: Actual agents count should be shown under Add agent flyout even if more than 20 agents are installed within 10 minutes of duration.

Screen Recording:

https://user-images.githubusercontent.com/77374876/183885102-0875ff6e-0a53-41f8-a204-813e05456b10.mp4

[elasticmachine]

Pinging @elastic/fleet (Team:Fleet)

[amolnater-qasource]

@manishgupta-qasource Please review.

[manishgupta-qasource]

Secondary review for this ticket is Done

[jen-huang]

We just query for the first 20 agents, I believe. Closing as won't fix as this is an edge case.

[amolnater-qasource]

Hi @jen-huang Thank you for the confirmation. We will be updating our test content accordingly.

Thanks!