rule(Delete or rename shell history):skip dockerfs

In some cases, when removing a container, dockerd will itself remove the
entire overlay filesystem, including a shell history file:

---
Shell history had been deleted or renamed (user=root type=unlinkat
command=dockerd -H fd://
... name=/var/lib/docker/overlay2/.../root/.bash_history ..
---

To avoid these FPs, skip paths starting with /var/lib/docker.

Signed-off-by: Mark Stemm <mark.stemm@gmail.com>

rules/falco_rules.yaml

@@ -2632,10 +2632,11 @@
       evt.arg.path contains "fish_read_history" or
       evt.arg.path endswith "fish_history")) or
     (open_write and (
+      (not fd.name startswith /var/lib/docker and (
       fd.name contains "bash_history" or
       fd.name contains "zsh_history" or
       fd.name contains "fish_read_history" or
-      fd.name endswith "fish_history") and evt.arg.flags contains "O_TRUNC")
+      fd.name endswith "fish_history")) and evt.arg.flags contains "O_TRUNC")
   output: >
     Shell history had been deleted or renamed (user=%user.name user_loginuid=%user.loginuid type=%evt.type command=%proc.cmdline fd.name=%fd.name name=%evt.arg.name path=%evt.arg.path oldpath=%evt.arg.oldpath %container.info)
   priority: