show serial for fully managed android (#40184)

<!-- Add the related story/sub-task/bug number, like Resolves #123, or
remove if NA -->
**Related issue:** Resolves #40116

This PR also fixes a weird bug that could cause a crash on host details
page, if hosts.users array was missing

<img width="1350" height="472" alt="image"
src="https://github.com/user-attachments/assets/48aba9a3-6145-4a0c-bab0-c99c3345040a"
/>


# Checklist for submitter

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

## Testing

- [x] Added/updated automated tests
- [x] QA'd all new/changed functionality manually

frontend/pages/hosts/details/HostDetailsPage/HostDetailsPage.tsx

@@ -669,7 +669,7 @@ const HostDetailsPage = ({
   useEffect(() => {
     setUsersState(() => {
       return (
-        host?.users.filter((user) => {
+        host?.users?.filter((user) => {
           return user.username
             .toLowerCase()
             .includes(usersSearchString.toLowerCase());

frontend/pages/hosts/details/cards/Vitals/Vitals.tests.tsx

@@ -9,18 +9,19 @@ import { DEFAULT_EMPTY_CELL_VALUE } from "utilities/constants";
 import Vitals from "./Vitals";
 
 describe("Vitals Card component", () => {
-  it("renders only the device Hardware model for Android hosts that were not enrolled in MDM personally", () => {
+  it("renders the device Hardware model and Serial number for Android hosts that were not enrolled in MDM personally", () => {
     const mockHost = createMockHost({
       platform: "android",
       hardware_model: "Pixel 6",
-      hardware_serial: "",
+      hardware_serial: "1234567890",
     });
 
     render(<Vitals vitalsData={mockHost} mdm={mockHost.mdm} />);
 
     expect(screen.getByText("Hardware model")).toBeInTheDocument();
     expect(screen.getByText("Pixel 6")).toBeInTheDocument();
-    expect(screen.queryByText("Serial number")).not.toBeInTheDocument();
+    expect(screen.getByText("Serial number")).toBeInTheDocument();
+    expect(screen.getByText("1234567890")).toBeInTheDocument();
     expect(screen.queryByText("Enrollment ID")).not.toBeInTheDocument();
     expect(screen.queryByText("Private IP address")).not.toBeInTheDocument();
     expect(screen.queryByText("Public IP address")).not.toBeInTheDocument();

frontend/pages/hosts/details/cards/Vitals/Vitals.tsx

@@ -309,38 +309,34 @@ const Vitals = ({
     }
 
     // Device identity
-    if (!(isAndroidHost && mdm && mdm.enrollment_status !== "On (personal)")) {
-      if (mdm && isBYODAccountDrivenUserEnrollment(mdm.enrollment_status)) {
-        //  Personal (BYOD) devices do not report their serial numbers, so show the enrollment id instead.
-        vitals.push({
-          sortKey: "Enrollment ID",
-          element: (
-            <DataSet
-              key="enrollment-id"
-              title={
-                <TooltipWrapper tipContent="Enrollment ID is a unique identifier for personal hosts. Personal (BYOD) devices don't report their serial numbers. The Enrollment ID changes with each enrollment.">
-                  Enrollment ID
-                </TooltipWrapper>
-              }
-              value={<TooltipTruncatedText value={vitalsData.uuid} />}
-            />
-          ),
-        });
-      } else {
-        // for all other host types, show the serial number
-        vitals.push({
-          sortKey: "Serial number",
-          element: (
-            <DataSet
-              key="serial-number"
-              title="Serial number"
-              value={
-                <TooltipTruncatedText value={vitalsData.hardware_serial} />
-              }
-            />
-          ),
-        });
-      }
+    if (mdm && isBYODAccountDrivenUserEnrollment(mdm.enrollment_status)) {
+      //  Personal (BYOD) devices do not report their serial numbers, so show the enrollment id instead.
+      vitals.push({
+        sortKey: "Enrollment ID",
+        element: (
+          <DataSet
+            key="enrollment-id"
+            title={
+              <TooltipWrapper tipContent="Enrollment ID is a unique identifier for personal hosts. Personal (BYOD) devices don't report their serial numbers. The Enrollment ID changes with each enrollment.">
+                Enrollment ID
+              </TooltipWrapper>
+            }
+            value={<TooltipTruncatedText value={vitalsData.uuid} />}
+          />
+        ),
+      });
+    } else {
+      // for all other host types, show the serial number
+      vitals.push({
+        sortKey: "Serial number",
+        element: (
+          <DataSet
+            key="serial-number"
+            title="Serial number"
+            value={<TooltipTruncatedText value={vitalsData.hardware_serial} />}
+          />
+        ),
+      });
     }
 
     // Hardware model