fix: use better data for the mdm enrollment activity for windows hosts, if it exists (#24392)

> Related issue: #23982

# 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://github.com/fleetdm/fleet/blob/main/docs/Contributing/Committing-Changes.md#changes-files)
for more information.
- [x] Added/updated tests
- [x] Manual QA for all new/changed functionality

server/service/integration_mdm_test.go

@@ -6586,12 +6586,12 @@ func (s *integrationMDMTestSuite) TestValidRequestSecurityTokenRequestWithDevice
 	// Checking if an activity was created for the enrollment
 	s.lastActivityOfTypeMatches(
 		fleet.ActivityTypeMDMEnrolled{}.ActivityName(),
-		`{
+		fmt.Sprintf(`{
 			"mdm_platform": "microsoft",
-			"host_serial": "",
+			"host_serial": "%s",
 			"installed_from_dep": false,
-			"host_display_name": "DESKTOP-0C89RC0"
-		 }`,
+			"host_display_name": "%s"
+		 }`, windowsHost.HardwareSerial, windowsHost.DisplayName()),
 		0)
 
 	expectedDeviceID := "AB157C3A18778F4FB21E2739066C1F27" // TODO: make the hard-coded deviceID in `s.newSecurityTokenMsg` configurable

server/service/microsoft_mdm.go

@@ -28,6 +28,7 @@ import (
 	mdmlifecycle "github.com/fleetdm/fleet/v4/server/mdm/lifecycle"
 	microsoft_mdm "github.com/fleetdm/fleet/v4/server/mdm/microsoft"
 	"github.com/fleetdm/fleet/v4/server/mdm/microsoft/syncml"
+	"github.com/fleetdm/fleet/v4/server/ptr"
 	kitlog "github.com/go-kit/log"
 	"github.com/go-kit/log/level"
 
@@ -1798,6 +1799,8 @@ func (svc *Service) storeWindowsMDMEnrolledDevice(ctx context.Context, userID st
 
 	// TODO: azure enrollments come with an empty uuid, I haven't figured
 	// out a good way to identify the device.
+	displayName := reqDeviceName
+	var serial string
 	if hostUUID != "" {
 		mdmLifecycle := mdmlifecycle.New(svc.ds, svc.logger)
 		err = mdmLifecycle.Do(ctx, mdmlifecycle.HostOptions{
@@ -1808,12 +1811,34 @@ func (svc *Service) storeWindowsMDMEnrolledDevice(ctx context.Context, userID st
 		if err != nil {
 			return err
 		}
+
+		// Get the host in order to get the correct display name and serial number for the activity
+		adminTeamFilter := fleet.TeamFilter{
+			User: &fleet.User{GlobalRole: ptr.String(fleet.RoleAdmin)},
+		}
+
+		hosts, err := svc.ds.ListHostsLiteByUUIDs(ctx, adminTeamFilter, []string{hostUUID})
+		if err != nil {
+			// Do not abort; this call was only made to get better data for the activity, so shouldn't
+			// fail the request. We fall back to `reqDeviceName` for the display name in this case.
+			logging.WithExtras(logging.WithNoUser(ctx),
+				"msg", "failed to get host data for windows MDM enrollment activity",
+			)
+		}
+
+		if len(hosts) == 1 {
+			// then we found the host, so use the data from there for the activity
+			displayName = hosts[0].DisplayName()
+			serial = hosts[0].HardwareSerial
+		}
+
 	}
 
 	err = svc.NewActivity(
 		ctx, nil, &fleet.ActivityTypeMDMEnrolled{
-			HostDisplayName: reqDeviceName,
+			HostDisplayName: displayName,
 			MDMPlatform:     fleet.MDMPlatformMicrosoft,
+			HostSerial:      serial,
 		})
 	if err != nil {
 		// only logging, the device is enrolled at this point, and we