tests: add CVM test for virtio_block_dynamic_vhdx_expand

Add a CVM variant of the virtio block dynamic VHDX expand
test in integration_cvm.rs. This test creates a
confidential guest and invokes the shared
_test_virtio_block_dynamic_vhdx_expand() wrapper to
validate VHDX expansion under CVM.

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

cloud-hypervisor/tests/integration_cvm.rs

@@ -194,4 +194,10 @@ mod common_cvm {
         );
         _test_virtio_block(&guest, false, false, true, true, ImageType::Qcow2);
     }
+
+    #[test]
+    fn test_virtio_block_dynamic_vhdx_expand() {
+        let guest = basic_cvm_guest!(JAMMY_IMAGE_NAME);
+        _test_virtio_block_dynamic_vhdx_expand(&guest);
+    }
 }