bsc: Add testscase & infra to validate Osmux support BTS<->BSC

New TC_assignment_osmux_bts is added which tests Osmux used only
BTS<->BSC.
Existing TC_assignment_osmux is renamed to TC_assignment_osmux_cn,
and a new TC_assignment_osmux is added which tests using Osmux on both
sides (towards BTS and CN).

Related: SYS#5987
Change-Id: I6e82eb9d995de988b812001e1c4cf6923509de66
diff --git a/bsc/expected-results.xml b/bsc/expected-results.xml
index 23217ba..223800b 100644
--- a/bsc/expected-results.xml
+++ b/bsc/expected-results.xml
@@ -106,6 +106,7 @@
   <testcase classname='BSC_Tests' name='TC_assignment_sdcch_exhausted_req_signalling_tch_forbidden' time='MASKED'/>
   <testcase classname='BSC_Tests' name='TC_assignment_sdcch_exhausted_req_voice_tch_forbidden' time='MASKED'/>
   <testcase classname='BSC_Tests' name='TC_assignment_osmux' time='MASKED'/>
+  <testcase classname='BSC_Tests' name='TC_assignment_osmux_bts' time='MASKED'/>
   <testcase classname='BSC_Tests' name='TC_rll_est_ind_inact_lchan' time='MASKED'/>
   <testcase classname='BSC_Tests' name='TC_rll_est_ind_inval_sapi1' time='MASKED'/>
   <testcase classname='BSC_Tests' name='TC_rll_est_ind_inval_sapi3' time='MASKED'/>