cbc: Test ETWS msg over CBSP

So far only non-emergency CBS messages were tested, which require a
slighlty idfferent encoding on the protocol side.

Related: OS#4945
Change-Id: Ie22a00120218a205db11a5622274dcc67435f5de
diff --git a/cbc/CBS_Message.ttcn b/cbc/CBS_Message.ttcn
index 1ce6935..faaa403 100644
--- a/cbc/CBS_Message.ttcn
+++ b/cbc/CBS_Message.ttcn
@@ -26,7 +26,7 @@
 	uint16_t ser_nr,
 	uint16_t old_ser_nr optional,
 	BSSMAP_FIELD_CellIdentificationList cell_list,
-	uint8_t channel_ind,
+	uint8_t channel_ind optional,
 	CBSP_Category category,
 	uint16_t rep_period,
 	uint16_t num_bcast_req,
@@ -39,4 +39,12 @@
 };
 type record of CBS_MessageContent CBS_MessageContents;
 
+function msg_id_is_etws(uint16_t msg_id) return boolean
+{
+	if (msg_id >= 4352 and msg_id <= 4359) {
+		return true;
+	}
+	return false;
+}
+
 }