ui: restart if crash (#36746)

* simpler

* mypy your are going to be replaced very soon

system/manager/manager.py

@@ -155,6 +155,10 @@ def manager_thread() -> None:
     print(running)
     cloudlog.debug(running)
 
+    if 'ui' in managed_processes and managed_processes['ui'].proc is not None and not managed_processes['ui'].proc.is_alive():
+      cloudlog.error(f'Restarting UI (exitcode {managed_processes["ui"].proc.exitcode})')
+      managed_processes['ui'].restart()
+
     # send managerState
     msg = messaging.new_message('managerState', valid=True)
     msg.managerState.processes = [p.get_process_state_msg() for p in managed_processes.values()]