TT#105871 Check for ngcp-io-scheduler.service instead of its alias io-scheduler.service

Check for ngcp-io-scheduler.service instead of io-scheduler.service,
as more recent versions of systemd (as present in Debian/bullseye)
resolve aliases and no longer report them as enabled but as alias.

State on Debian/buster:

| sipwise@spce:~$ systemctl list-unit-files '*scheduler*'
| UNIT FILE                 STATE
| io-scheduler.service      enabled
| ngcp-io-scheduler.service enabled
|
| 2 unit files listed.

State on Debian/bullseye:

| root@spce:~# systemctl list-unit-files '*scheduler*'
| UNIT FILE                 STATE   VENDOR PRESET
| io-scheduler.service      alias   -
| ngcp-io-scheduler.service enabled enabled
|
| 2 unit files listed.

Change-Id: I57b1b68dce32290055aa216084287aa314fc0de5

templates/500_init-daemons-dabian.yaml.tt2

@@ -35,10 +35,6 @@ service:
     enabled: true
     running: true
 
-  io-scheduler.service:
-    enabled: true
-    running: true
-
   influxdb.service:
     enabled: [% monitoring.backend == 'influxdb' || monitoring.influxdb_migrated == 'no' ? 'true' : 'false' %]
     running: [% monitoring.backend == 'influxdb' || monitoring.influxdb_migrated == 'no' ? 'true' : 'false' %]
@@ -57,6 +53,10 @@ service:
     running: true
 {{end}}
 
+  ngcp-io-scheduler.service:
+    enabled: true
+    running: true
+
   rsyslog.service:
     enabled: true
     running: true