Fixed introduced error with double encoding

Author: Alveel

minio/minioadmin.py

@@ -458,13 +458,13 @@ def policy_add(self,
                    policy_file: str | None = None,
                    policy: dict | None = None) -> str:
         """Add new policy."""
-        if not (policy_file is not None) ^ (policy is not None):
-            raise ValueError("either policy or policy_file must be specified")
-        if policy:
-            body = json.dumps(policy).encode()
         if policy_file:
             with Path(policy_file).open(encoding='utf-8') as file:
                 body = file.read().encode()
+        elif policy:
+            body = json.dumps(policy).encode()
+        else:
+            raise ValueError("either policy or policy_file must be specified")
 
         response = self._url_open(
             "PUT",
@@ -473,7 +473,7 @@ def policy_add(self,
             # Disabled check because this code is never reached if body is not
             # defined.
             # pylint: disable-next=possibly-used-before-assignment
-            body=json.dumps(body).encode(),
+            body=body,
         )
         return response.data.decode()