Add a Fleet-maintained app in teams/ YAML file

[noahtalerman]

Goal

User story
As an admin,
I want to be able to add Fleet-maintained apps using YAML
so that I can add apps and auto-install them without using UI and so that I can keep things updated if I'm running everything through GitOps.

Key result

Deliver prioritized customer requests

Original requests

• Fleet-maintained apps via GitOps #24342

Context

• Product designer: @eugkuo

Changes

Product

• UI changes: No changes
• CLI (fleetctl) usage changes: No changes
• YAML changes: [YAML docs] Add ability to add Fleet-maintained apps via YAML. #24648
• Fleet's agent (fleetd) changes: No changes.
• Activity changes: Add applied_spec_software for YAML software updates #24913
• Permissions changes: No changes
• Changes to paid features or tiers: Available for Fleet Premium.
• First draft of test plan added
• Other reference documentation changes: No changes
• Once shipped, requester has been notified
• Once shipped, dogfooding issue has been filed

Engineering

• Test plan is finalized
• Feature guide changes: TODO
• Database schema migrations: TODO
• Load testing: TODO
• REST API changes: TODO

ℹ️  Please read this issue carefully and understand it. Pay special attention to UI wireframes, especially "dev notes".

QA

Risk assessment

• Requires load testing: TODO
• Risk level: Low / High TODO
• Risk description: TODO

Test plan

1. Case 1
   1. Add a FMA in UI
   2. YAML does not have the same FMA configured
   3. Run GitOps. Result: removes the FMA from host.
2. Case 2
   1. No FMA added in UI.
   2. Add same FMA in YAML
   3. Run GitOps. Result: FMA is scoped to correct team and shows up in software list.
3. Case 3
   1. Add FMA with auto-install in UI
   2. Add same FMA in YAML
   3. Run GitOps. Result: Does not change auto-install state.

Testing notes

Confirmation

1. Engineer: Added comment to user story confirming successful completion of test plan.
2. QA: Added comment to user story confirming successful completion of test plan.