Increase the thread heartbeat timeout

Summary: OSFP optics are taking a little longer to program. The delay gets long and over the current hearbeat threshold sometimes when we have 8 ports to program in an optic. This causes qsfp tests to fail. Increasing the timeout for now until we can optimize the programming on these optics (if at all it is possible)

Reviewed By: xanabani

Differential Revision: D61987557

fbshipit-source-id: 29495c83b93105b850a78cf0cde7cac067d72e86

fboss/qsfp_service/TransceiverManager.cpp

@@ -36,7 +36,7 @@ DEFINE_bool(
 
 DEFINE_int32(
     state_machine_update_thread_heartbeat_ms,
-    10000,
+    20000,
     "State machine update thread's heartbeat interval (ms)");
 
 DEFINE_bool(