Add keystore_key:attest_unique_id to priv_app.

Only privileged apps are supposed to be able to get unique IDs from
attestation.

Test: CTS test verifies the negative condition, manual the positive
Bug: 34671471
Change-Id: I9ab3f71b1e11ed1d7866ff933feece73152d2578
diff --git a/private/access_vectors b/private/access_vectors
index dcd86c2..6b08d9e 100644
--- a/private/access_vectors
+++ b/private/access_vectors
@@ -702,6 +702,7 @@
 	clear_uid
 	add_auth
 	user_changed
+	gen_unique_id
 }
 
 class drmservice {