Uploading new installer to FMA turns FMA to custom package

[RachelElysia]

Issue

Closes #28687

Description

• When uploading a new package to a FMA, turn the FMA into a custom package

Screenrecording of fix

Screen.Recording.2025-06-12.at.9.52.42.AM.mov

Checklist for submitter

If some of the following don't apply, delete the relevant line.

• Changes file added for user-visible changes in changes/, orbit/changes/ or ee/fleetd-chrome/changes.
  See Changes files for more information.
• Added/updated automated tests
• Manual QA for all new/changed functionality

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 64.11%. Comparing base (e44f454) to head (46ab2c0).
Report is 31 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #29959      +/-   ##
==========================================
- Coverage   64.18%   64.11%   -0.07%     
==========================================
  Files        1859     1863       +4     
  Lines      181882   182317     +435     
  Branches     5331     5331              
==========================================
+ Hits       116734   116892     +158     
- Misses      55965    56224     +259     
- Partials     9183     9201      +18     

Flag	Coverage Δ
backend	65.05% <100.00%> (-0.08%)	⬇️

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[RachelElysia]

@iansltx -- is there something I'm missing to make the last two tests pass?

[iansltx]

In addition to the feedback here (which should drastically shrink the PR), we should cover this with tests. With the suggested implementation, a data store test should be sufficient as long as you can get an FMA set up in the "arrange" part of the test.

[iansltx]

This should be around L480, or probably part of ds.SaveInstallerUpdates, specifically the touchUploaded override. I believe that turns this change into a one-liner (since we can unconditionally null out FMA ID there), plus tests.

[iansltx]

IIRC docs are broken here because a PR upstream hasn't been merged due to lack of approver availability, so not concerned about that since the other tests are passing.

[iansltx]

Guessing this is breaking tests. FMA table needs to have something in it to satisfy the foreign key constraint.

[iansltx]

@RachelElysia I confirmed the test failure was what I expected it to be, so that needs to be fixed (so tests pass) before this merges.

=== RUN   TestSoftwareInstallers/SaveInstallerUpdatesClearsFleetMaintainedAppID
    software_installers_test.go:3117: 
        	Error Trace:	/Volumes/Code/CH/fleet/server/datastore/mysql/software_installers_test.go:3117
        	            				/Volumes/Code/CH/fleet/server/datastore/mysql/software_installers_test.go:57
        	Error:      	Received unexpected error:
        	            	Error 1452 (23000): Cannot add or update a child row: a foreign key constraint fails ("server_datastore_mysql_TestSoftwareInstallers"."software_installers", CONSTRAINT "software_installers_ibfk_1" FOREIGN KEY ("fleet_maintained_app_id") REFERENCES "fleet_maintained_apps" ("id"))
        	Test:       	TestSoftwareInstallers/SaveInstallerUpdatesClearsFleetMaintainedAppID
--- FAIL: TestSoftwareInstallers/SaveInstallerUpdatesClearsFleetMaintainedAppID (0.92s)

[iansltx]

Thanks for the tweaks!