Adds a new Build Id into a new set, which will be used as the default set for the queue. This means all new workflows will start on this Build Id.

Class Variable	build_id	Undocumented
Method	_as_partial_proto	Returns a partial request with the operation populated. Caller must populate non-operation fields. This is done b/c there's no good way to assign a non-primitive message as the operation after initializing the request.

Returns a partial request with the operation populated. Caller must populate non-operation fields. This is done b/c there's no good way to assign a non-primitive message as the operation after initializing the request.