feat: backend for VPP related global activities (#20484)

> Related issue: #19870 

# Checklist for submitter

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

<!-- Note that API documentation changes are now addressed by the
product design team. -->

- [x] Changes file added for user-visible changes in `changes/`,
`orbit/changes/` or `ee/fleetd-chrome/changes`.
See [Changes
files](https://fleetdm.com/docs/contributing/committing-changes#changes-files)
for more information.
- [x] Added/updated tests
- [x] Manual QA for all new/changed functionality

ee/server/service/vpp.go

@@ -7,6 +7,7 @@ import (
 	"fmt"
 	"net/http"
 
+	"github.com/fleetdm/fleet/v4/server/authz"
 	"github.com/fleetdm/fleet/v4/server/contexts/ctxerr"
 	"github.com/fleetdm/fleet/v4/server/fleet"
 	"github.com/fleetdm/fleet/v4/server/mdm/apple/itunes"
@@ -159,5 +160,15 @@ func (svc *Service) AddAppStoreApp(ctx context.Context, teamID *uint, adamID str
 		return ctxerr.Wrap(ctx, err, "writing VPP app to db")
 	}
 
+	act := fleet.ActivityAddedAppStoreApp{
+		AppStoreID:    app.AdamID,
+		TeamName:      &teamName,
+		SoftwareTitle: app.Name,
+		TeamID:        teamID,
+	}
+	if err := svc.NewActivity(ctx, authz.UserFromContext(ctx), act); err != nil {
+		return ctxerr.Wrap(ctx, err, "create activity for add app store app")
+	}
+
 	return nil
 }