tests: Add virtio vsock test for confidential VMs

Add test_virtio_vsock to the common_cvm integration test module
to verify that virtio vsock functionality works correctly in
confidential guest environments.

The test creates an Ubuntu Jammy-based confidential VM using
GuestFactory and delegates to the existing _test_virtio_vsock
helper with hotplug disabled.

Signed-off-by: Muminul Islam <muislam@microsoft.com>

cloud-hypervisor/tests/integration.rs

@@ -14938,4 +14938,12 @@ mod common_cvm {
             GuestFactory::new_confidential_guest_factory().create_guest(Box::new(disk_config));
         _test_power_button(&guest);
     }
+
+    #[test]
+    fn test_virtio_vsock() {
+        let disk_config = UbuntuDiskConfig::new(JAMMY_IMAGE_NAME.to_string());
+        let guest =
+            GuestFactory::new_confidential_guest_factory().create_guest(Box::new(disk_config));
+        _test_virtio_vsock(&guest, false);
+    }
 }