bsc: replace octet string with decmatch when matching RR RELEASE

The 'decmatch' keyword allows us to match the decoded version of some
octetstring, which is very useful in the situations where we have
the L3 message only as octetstring but want to check if it matches
some L3 template.

Change-Id: I0a91e067f7e8062bf991fef8b0d4d8da740bfafc
diff --git a/bsc/BSC_Tests_LCLS.ttcn b/bsc/BSC_Tests_LCLS.ttcn
index 0fada93..67ccecf 100644
--- a/bsc/BSC_Tests_LCLS.ttcn
+++ b/bsc/BSC_Tests_LCLS.ttcn
@@ -702,7 +702,7 @@
 	var myBSSMAP_Cause cause_val := GSM0808_CAUSE_CALL_CONTROL;
 	CONN_A.send(ts_BSSMAP_ClearCommand(enum2int(cause_val)));
 	interleave {
-	[] CONN_A.receive(tr_RSL_DATA_REQ(?, tr_RslLinkID_DCCH(0), t_l3_rr_chan_rel));
+	[] CONN_A.receive(tr_RSL_DATA_REQ(?, tr_RslLinkID_DCCH(0), decmatch tr_RRM_RR_RELEASE));
 	[] CONN_A.receive(tr_RSL_DEACT_SACCH(?));
 	[] CONN_A.receive(tr_RSL_RF_CHAN_REL(?)) -> value rsl {
 		var RSL_IE_Body ieb;