Add cross-language tests with KMS AEAD with Tink prefix.

In tink-crypto/tink-go#10 it
was mentioned that KMS Envelope Keys can and are used with a TINK prefix. And the same is probably true for KMS AEAD keys.

Add this test to make sure that all languages that currently support this are consistent. At the moment it does not work in Java.

PiperOrigin-RevId: 617204124
Change-Id: I5203daf1fdea2ac883f3269e498057f679ed0ce2

cross_language/cross_language/BUILD.bazel

@@ -90,6 +90,7 @@ py_test(
         requirement("absl-py"),
         "@tink_py//tink:tink_python",
         "@tink_py//tink/aead",
+        "@tink_py//tink/proto:kms_aead_py_pb2",
         "@tink_py//tink/proto:kms_envelope_py_pb2",
         "@tink_py//tink/proto:tink_py_pb2",
         "@tink_py//tink/testing:keyset_builder",

cross_language/cross_language/aead_test.py

@@ -24,6 +24,7 @@
 import tink
 from tink import aead
 
+from tink.proto import kms_aead_pb2
 from tink.proto import kms_envelope_pb2
 from tink.proto import tink_pb2
 from tink.testing import keyset_builder
@@ -138,6 +139,19 @@ def tearDownModule():
         # TODO(b/329404375): This currently fails in Java.
         ['cc', 'go', 'python'],
     ),
+    '_FAKE_KMS_AEAD_WITH_TINK_PREFIX': (
+        tink_pb2.KeyTemplate(
+            value=kms_aead_pb2.KmsAeadKeyFormat(
+                key_uri=_FAKE_KMS_KEY_URI,
+            ).SerializeToString(),
+            type_url=(
+                'type.googleapis.com/google.crypto.tink.KmsAeadKey'
+            ),
+            output_prefix_type=tink_pb2.TINK,
+        ),
+        # TODO(b/329404375): This currently fails in Java.
+        ['cc', 'go', 'python'],
+    ),
 }