Get aggregated statistics for all rules for a given firewall section. The
API only supports access to cached (source=cached) statistical data
collected offline in the system. Data includes total number of packets,
bytes, sessions counters and popularity index for a firewall rule and
overall session count, max session count and max popularity index for
all firewall rules on transport nodes or edge nodes. Aggregated
statistics like maximum popularity index, maximum session count and
total session count are computed with lower frequency compared to
individual generic rule statistics, hence they may have a computation
delay up to 15 minutes to reflect in response to this API.