osmo-bsc: Parametrize codec-list VTY cfg

Change-Id: I1678aba43e8d399ecad192cbc416698373e3c0a0
diff --git a/example/defaults.conf b/example/defaults.conf
index 61b09fb..5bdf257 100644
--- a/example/defaults.conf
+++ b/example/defaults.conf
@@ -14,6 +14,8 @@
     short_name: osmo-gsm-tester-msc
     long_name: osmo-gsm-tester-msc
     encryption: a5_0
+    codec_list:
+    - hr3
 
 msc:
   net: