Revert "Disable cert validation in tests until b/263254184 is fixed"

This reverts commit c16d6cd77f201978c54d7b2a761c68cb76c60ff7.

Reason for revert: Root cause has been resolved

Change-Id: Ief83cceb607fa72ca4602588e18d3d06779d027c
diff --git a/keystore2/tests/keystore2_client_attest_key_tests.rs b/keystore2/tests/keystore2_client_attest_key_tests.rs
index bfa0495..fc3148c 100644
--- a/keystore2/tests/keystore2_client_attest_key_tests.rs
+++ b/keystore2/tests/keystore2_client_attest_key_tests.rs
@@ -172,9 +172,7 @@
         let mut cert_chain: Vec<u8> = Vec::new();
         cert_chain.extend(attestation_key_metadata.certificate.as_ref().unwrap());
         cert_chain.extend(attestation_key_metadata.certificateChain.as_ref().unwrap());
-        // The server seems to be issuing test certs with invalid subject names.
-        // Re-enable when b/263254184 is fixed
-        // validate_certchain(&cert_chain).expect("Error while validating cert chain.");
+        validate_certchain(&cert_chain).expect("Error while validating cert chain.");
 
         // Create EC key and use attestation key to sign it.
         let ec_key_alias = format!("ks_ec_attested_test_key_{}", getuid());
@@ -192,9 +190,7 @@
         cert_chain.extend(attestation_key_metadata.certificate.as_ref().unwrap());
         cert_chain.extend(attestation_key_metadata.certificateChain.as_ref().unwrap());
 
-        // The server seems to be issuing test certs with invalid subject names.
-        // Re-enable when b/263254184 is fixed
-        // validate_certchain(&cert_chain).expect("Error while validating cert chain.");
+        validate_certchain(&cert_chain).expect("Error while validating cert chain.");
     }
 }