Make library 'libkeystore_attestation' available to /vendor

We would like to construct the standard formatted value for
ATTESTATION_APPLICATION_ID using
`keystore_attestation::{AttestationApplicationId, PackageInfoRecord}`
from /vendor partition and call KeyMint API

Bug: 396315736

Test: m
Change-Id: Ie7bff59c6a662c0f9b342dc76e87bf4eb7b1da95
diff --git a/keystore2/test_utils/attestation/Android.bp b/keystore2/test_utils/attestation/Android.bp
index dbf02d0..0ac5630 100644
--- a/keystore2/test_utils/attestation/Android.bp
+++ b/keystore2/test_utils/attestation/Android.bp
@@ -40,6 +40,7 @@
 rust_library {
     name: "libkeystore_attestation",
     defaults: ["libkeystore_attestation_defaults"],
+    vendor_available: true,
 }
 
 rust_test {