Schedules a background re-synchronization of all of the chatbot's imported (help-center / integration-sourced)
knowledge base policies and returns immediately. Policies in READY_TO_INGEST status are left untouched.
Only one synchronization per chatbot can be scheduled or running at a time - while one is, the call returns
ALREADY_IN_PROGRESS and nothing new is scheduled. Use the knowledge base sync endpoint to synchronize
a single knowledge base and get the result.