rsyslog to start after interfaces-config (#13503)

Fixes #12408

Why I did it
We are running into #12408 very frequently.
This results in no syslogs from any containers as rsyslog server could not start.
some of the sonic-mgmt scripts look for log statements and error out if log is not present.

Interfaces-config service configures the loopback interface along with other interfaces. rsyslog-config reads ip address of loopback interface and generates /etc/rsyslog.conf. When this race condition happens, lo interface ip is not yet programmed and rsyslog-config ends up writing UDP server as null in /etc/rsyslog.conf.

How I did it
rsyslog-config service is started after interfaces-config service.

How to verify it
Did multiple reboots and verified that $UDPServerAddress is valid.

files/image_config/rsyslog/rsyslog-config.service

@@ -4,6 +4,7 @@ Requires=updategraph.service
 After=updategraph.service
 BindsTo=sonic.target
 After=sonic.target
+After=interfaces-config.service
 
 [Service]
 Type=oneshot