update auth flow

Author: arithmetic1728

google/oauth2/gdch_credentials.py

@@ -118,11 +118,16 @@ def __init__(
         self._quota_project_id = quota_project_id
 
     def _make_k8s_token_request(self, request):
+        k8s_request_body = {
+            "kind": "TokenRequest",
+            "apiVersion": "authentication.k8s.io/v1",
+            "spec": {"audiences": [self._ais_token_endpoint]},
+        }
         # mTLS connection to k8s token endpoint to get a k8s token.
         k8s_response_data = _client._token_endpoint_request(
             request,
             self._k8s_token_endpoint,
-            {},
+            k8s_request_body,
             None,
             True,
             http_client.CREATED,

tests/oauth2/test_gdch_credentials.py

@@ -75,7 +75,11 @@ def test__make_k8s_token_request(self, token_endpoint_request):
         token_endpoint_request.assert_called_with(
             req,
             creds._k8s_token_endpoint,
-            {},
+            {
+                "kind": "TokenRequest",
+                "apiVersion": "authentication.k8s.io/v1",
+                "spec": {"audiences": [creds._ais_token_endpoint]},
+            },
             None,
             True,
             http_client.CREATED,