Disable the Zeek stats log

"zeekctl cron" writes node statistics to /nsm/zeek/logs/stats. The CPU and memory
half comes from a helper that shells out to top, which the Zeek container does not
include. The helper's "command not found" output is then parsed as process data, so
every cron run appended a line per node reading "bad output from top", which
so-log-check reports.

Nothing wrote that file before, since log_stats and update_http_stats only run from
"zeekctl cron". Set StatsLogEnable to 0 so neither runs, and mark it read only since
the CPU and memory statistics cannot work with this image. The interface counters it
also collects are not used anywhere in Security Onion, which tracks Zeek packet loss
separately through packetloss.log and Telegraf, so nothing is lost by turning this
off. Note in StatsLogExpireInterval that it does nothing while the stats log is off.

salt/zeek/defaults.yaml

@@ -15,7 +15,7 @@ zeek:
       MailHostUpDown: 0
       LogRotationInterval: 3600
       LogExpireInterval: 0
-      StatsLogEnable: 1
+      StatsLogEnable: 0
       StatsLogExpireInterval: 0
       StatusCmdShowAll: 0
       CrashExpireInterval: 0

salt/zeek/soc_zeek.yaml

@@ -69,10 +69,24 @@ zeek:
         regexFailureMessage: Enter 0, or a positive number optionally followed by "day" or "hr" (for example 7, "7 days", or "12 hr"). Minutes are not accepted because a log expire interval shorter than the log rotation interval prevents Zeek from starting.
         helpLink: zeek
         advanced: True
+      StatsLogEnable:
+        description: >-
+          Set to 1 to have "zeekctl cron" write node statistics to /nsm/zeek/logs/stats. This is
+          disabled because the CPU and memory portion depends on the "top" command, which the Zeek
+          container does not include, so every run records an error for each node instead. The
+          interface packet counters it also collects are not used anywhere in Security Onion, which
+          tracks Zeek packet loss separately through packetloss.log and Telegraf. It is read only
+          for that reason.
+        regex: ^[01]$
+        regexFailureMessage: You must enter 0 or 1.
+        helpLink: zeek
+        advanced: True
+        readonly: True
       StatsLogExpireInterval:
         description: >-
           Number of days to keep entries in the Zeek stats log, or 0 to keep them forever.
-          Applied by "zeekctl cron", which runs every 5 minutes.
+          Applied by "zeekctl cron", which runs every 5 minutes. This has no effect unless
+          StatsLogEnable is turned on, which it is not by default.
         regex: ^[0-9]+$
         regexFailureMessage: You must enter a whole number of days, or 0 to keep entries forever.
         helpLink: zeek