add ran_infra.force_mgw_codecs_to_ran

Indicate in the ran_infra data structure whether a RAN needs specific
codecs to be set up on the RAN facing MGW endpoint.

This allows setting forced RAN codecs as first-class citizen in the
ran_infra data structure, instead of special cases in the code (for IuUP
on IuCS).

Will be used in subsequent commit
I37f65c36af2679ecba1040a11a9aa0eb9481d817, submitted separately for
easier readability.

Change-Id: I37f65c36af2679ecba1040a11a9aa0eb9481d817
diff --git a/tests/msc_vlr/msc_vlr_tests.c b/tests/msc_vlr/msc_vlr_tests.c
index 6b80452..b0c60ed 100644
--- a/tests/msc_vlr/msc_vlr_tests.c
+++ b/tests/msc_vlr/msc_vlr_tests.c
@@ -408,6 +408,16 @@
 		.log_subsys = DIUCS,
 		.tdefs = msc_tdefs_utran,
 		.ran_encode = dont_ran_encode,
+		.force_mgw_codecs_to_ran = {
+			.count = 1,
+			.codec = {
+				{
+					.payload_type = 96,
+					.subtype_name = "VND.3GPP.IUFP",
+					.rate = 16000,
+				},
+			},
+		},
 	},
 };