Add container rsyslog.conf to the sys dump (sonic-net#3039)

What I did
Added a new directory to generate_dump for collecting any container specific config files etc to the sys dump. For now only the rsyslog.conf is added

How I did it
How to verify it
Run the dump and see if the rsyslogd files are present

root@r-leopard-41:/home/admin# tree -a sonic_dump_r-leopard-41_20230815_013600/dump/container_dumps/
sonic_dump_r-leopard-41_20230815_013600/dump/container_dumps/
├── bgp
│   └── rsyslog.conf
├── database
│   └── rsyslog.conf
├── dhcp_relay
│   └── rsyslog.conf
├── eventd
│   └── rsyslog.conf
├── lldp
│   └── rsyslog.conf
├── mgmt-framework
│   └── rsyslog.conf
├── pmon
│   └── rsyslog.conf
├── radv
│   └── rsyslog.conf
├── snmp
│   └── rsyslog.conf
├── swss
│   └── rsyslog.conf
├── syncd
│   └── rsyslog.conf
├── teamd
│   └── rsyslog.conf
└── telemetry
    └── rsyslog.conf

13 directories, 13 files

scripts/generate_dump

@@ -1670,6 +1670,22 @@ save_dump_state_all_ns() {
     done
 }
 
+###############################################################################
+# Save important files that are present in container storage for better debugging
+# Files will be saved under dump/<container_name>/
+# Types of Files Saved:
+# 1) rsyslogd.conf
+###############################################################################
+save_container_files() {
+    trap 'handle_error $? $LINENO' ERR
+    local CONTAINER_FDUMP="container_dumps"
+    # Get the running container names
+    container_names=$(docker ps --format '{{.Names}}' --filter status=running)
+    for name in $container_names; do
+        $MKDIR $V -p $LOGDIR/$CONTAINER_FDUMP/$name
+        copy_from_docker $name "/etc/rsyslog.conf" $LOGDIR/$CONTAINER_FDUMP/$name/rsyslog.conf
+    done
+}
 
 ###############################################################################
 # Main generate_dump routine
@@ -1797,6 +1813,8 @@ main() {
     wait
     save_redis_info &
 
+    save_container_files &
+
     if $DEBUG_DUMP
     then
         save_dump_state_all_ns &