bsc: add TC_ciph_mode_a5_2_1

Verify that A5/1 is preferred over A5/2. Add encr_exp_enc_alg to
MSC_ConnectionHandler:TestHdlrEncrParams, so the expected encryption
algorithm can be different from what the MSC tells the BSC about the
capabilities of MS.

Related: OS#4975
Change-Id: I688d056bcfe73f7846f908a28f4621f944cf2178
diff --git a/bsc/expected-results.xml b/bsc/expected-results.xml
index d2052b8..793ca03 100644
--- a/bsc/expected-results.xml
+++ b/bsc/expected-results.xml
@@ -54,6 +54,7 @@
   <testcase classname='BSC_Tests' name='TC_assignment_fr_a5_not_sup' time='MASKED'/>
   <testcase classname='BSC_Tests' name='TC_ciph_mode_a5_0' time='MASKED'/>
   <testcase classname='BSC_Tests' name='TC_ciph_mode_a5_1' time='MASKED'/>
+  <testcase classname='BSC_Tests' name='TC_ciph_mode_a5_2_1' time='MASKED'/>
   <testcase classname='BSC_Tests' name='TC_ciph_mode_a5_3' time='MASKED'/>
   <testcase classname='BSC_Tests' name='TC_ciph_mode_a5_4' time='MASKED'/>
   <testcase classname='BSC_Tests' name='TC_assignment_codec_fr' time='MASKED'/>