Make DTBO for VM containing vendor pubkey when vendor image exists

Bug: 285855436
Test: adb shell /apex/com.android.virt/bin/vm run-microdroid --vendor /data/local/tmp/test_microdroid_vendor_image.img
Test: atest virtualizationmanager_device_test

Change-Id: Ib1b8301d572d2546350fb1e5e9b11060b430b756
diff --git a/libs/vbmeta/Android.bp b/libs/vbmeta/Android.bp
index ae83703..4fb6ae4 100644
--- a/libs/vbmeta/Android.bp
+++ b/libs/vbmeta/Android.bp
@@ -18,6 +18,9 @@
 rust_library {
     name: "libvbmeta_rust",
     defaults: ["libvbmeta_rust.defaults"],
+    apex_available: [
+        "com.android.virt",
+    ],
 }
 
 rust_test_host {