osmo-bsc: Parametrize codec-list VTY cfg

Change-Id: I1678aba43e8d399ecad192cbc416698373e3c0a0
diff --git a/example/scenarios/cfg-codec-hr3.conf b/example/scenarios/cfg-codec-hr3.conf
new file mode 100644
index 0000000..c54b924
--- /dev/null
+++ b/example/scenarios/cfg-codec-hr3.conf
@@ -0,0 +1,5 @@
+config:
+  bsc:
+    net:
+      codec_list:
+      - hr3