fix: generate telemetry for host-mounted /sys/ paths in containers

[asmit27rai]

Problem

When a container has a host filesystem mount (e.g., /sys/kernel/security),
accessing files on that mount generates no alerts or system logs.

Root Cause

In KubeArmor/BPF/system_monitor.c, both kprobe__open and kprobe__openat
unconditionally dropped all file access events for paths starting with /sys/
via the isSysDir() check. This was intended to reduce host-level sysfs noise,
but it also silently dropped events from container processes accessing
host-mounted /sys/ paths.

Without save_args() being called in the kprobe, the corresponding kretprobe's
load_args() finds nothing → the event is never emitted → no telemetry.

Fix

• Added is_container_context() BPF helper that checks
  pid_ns != PROC_PID_INIT_INO to determine if the current process
  is running inside a container.
• Modified kprobe__open and kprobe__openat to only skip /sys/ paths
  for host processes. Container processes now have their /sys/ access
  events flow through normally.

Fixes #1851