Update sdks/python/apache_beam/utils/subprocess_server.py

Co-authored-by: Sergii Tkachenko <sergiitk@google.com>

Author: tvalentyn

sdks/python/apache_beam/utils/subprocess_server.py

@@ -189,7 +189,7 @@ def start(self):
           ("grpc.max_receive_message_length", -1),
           ("grpc.max_send_message_length", -1),
           # Default: 20000ms (20s), increased to 10 minutes for stability
-          ("grpc.keepalive_timeout_ms", 600000),
+          ("grpc.keepalive_timeout_ms", 600_000),
           # Default: 2, set to 0 to allow unlimited pings without data
           ("grpc.http2.max_pings_without_data", 0),
           # Default: False, set to True to allow keepalive pings when no calls