bsc: fix copy-paste in TC_lcls_gcr_bway_codec_mismatch
The comment says that:
* first call leg uses FR, * second call leg uses HR,
however the code actually modifies the first call leg to use HR.
The test still exercises a codec mismatch, so LCLS non-activation is still triggered, but the leg roles are swapped relative to the stated intent. Fix this to avoid confusion.
