BSC_Tests: use c_mr_conf_5_90 in TC_assignment_codec_amr_startmode_cruft

This way it's easier to see that the only difference from other
tests using c_mr_conf_5_90 is the ICMI field set to false.

Change-Id: If7b491fa55a9366520c2d665a700c5badb187fae
diff --git a/bsc/BSC_Tests.ttcn b/bsc/BSC_Tests.ttcn
index 3ed901a..f6f8c9c 100644
--- a/bsc/BSC_Tests.ttcn
+++ b/bsc/BSC_Tests.ttcn
@@ -4610,8 +4610,8 @@
 	pars.ass_codec_list := valueof(ts_BSSMAP_IE_CodecList({ts_CodecAMR_F}));
 	pars.ass_codec_list.codecElements[0].s0_7 := '00000100'B; /* 5,90k */
 	pars.ass_codec_list.codecElements[0].s8_15 := '01010111'B;
-	/* expect ICMI=0, smod=00: */
-	pars.expect_mr_conf_ie := valueof(RSL_IE_Body:{multirate_cfg := ts_RSL_MultirateCfg(false, 0, '00000100'B /* 5,90k */)});
+	pars.expect_mr_conf_ie := c_mr_conf_5_90;
+	pars.expect_mr_conf_ie.multirate_cfg.icmi := false; /* expect ICMI=0, smod=00: */
 
 	f_init(1, true);
 	f_sleep(1.0);