Fix EGPRS PUAN encoding: use correct urbb_len

Earlier there was an incorrect encoding of PUAN when VQ is not equal
VR case for EGPRS UL RLC window. The PCU was encoding the same PUAN
message always irrespective of radio condition. This was a bottle neck
for performance testing. Which has been fixed in this patch.

Related: OS#1793

unit test assertion in the previous commit is fixed in this patch.

Change-Id: Iba7b1995028bd81749ffb080616b2ad5f2540d57
3 files changed