PCUIF_Types: make PCUIF_info_ind field bts_model optional

The field bts_model has been introduced with PCUIF v12, which is now
used in master. In latest we still use PCUIF v11, where the bts_model
field is not present. This means that when we test against osmo-bts
latest there will be an error parsing PCUIF_info_ind. A solution to this
problem is to declare the bts_model field as an optional field until
PCUIF v12 is also used in latest.

Related: OS#6191
Change-Id: I45947f3bddaccafee82824ebb1b8494eabc67e7a
diff --git a/library/PCUIF_Types.ttcn b/library/PCUIF_Types.ttcn
index 12c704f..33b454f 100644
--- a/library/PCUIF_Types.ttcn
+++ b/library/PCUIF_Types.ttcn
@@ -212,7 +212,11 @@
 	record length(2) of uint16_t	remote_port,
 	PCUIF_RemoteAddr		remote_addr,
 
-	PCUIF_bts_model	bts_model
+	/* The bts_model field was introduced with PCUIF v12 as a new mandatory field. This also means that when we
+	 * use the testsuite to test against latest builds (still uses PCUIF v11) this field is not included in
+	 * the PCUIF_info_ind message. Since the testsuite does not check on this field we decided to declare the
+	 * field as an optional field until PCUIF v12 is also used in the latest builds.*/
+	PCUIF_bts_model	bts_model optional
 } with { variant "" };
 
 type enumerated PCUIF_AddrType {
@@ -992,7 +996,8 @@
 			local_port := ?,
 			remote_port := ?,
 			remote_addr := ?,
-			bts_model := ?
+			/* See note in record PCUIF_info_ind */
+			bts_model := *
 		}
 	}
 }