osmo-bsc: Parametrize codec-list VTY cfg

Change-Id: I1678aba43e8d399ecad192cbc416698373e3c0a0
diff --git a/src/osmo_gsm_tester/resource.py b/src/osmo_gsm_tester/resource.py
index e4e2f9d..15f2711 100644
--- a/src/osmo_gsm_tester/resource.py
+++ b/src/osmo_gsm_tester/resource.py
@@ -87,7 +87,8 @@
     RESOURCES_SCHEMA)
 
 CONF_SCHEMA = util.dict_add(
-    { 'defaults.timeout': schema.STR },
+    { 'defaults.timeout': schema.STR,
+      'config.bsc.net.codec_list[]': schema.CODEC },
     dict([('resources.%s' % key, val) for key, val in WANT_SCHEMA.items()]),
     dict([('modifiers.%s' % key, val) for key, val in WANT_SCHEMA.items()]))