EGPRS: PUAN encoding: add test case to show wrong urbb_len issue

This patch adds a test case which expects a current bug with EGPRS PUAN
encoding when VQ != VR. The test's expectation is corrected along with
the bugfix in a subsequent commit

Adds test_tbf_puan_urbb_len to describe the following bug:
EGPRS PUAN encoding disregards the urbb_len, leading to identical PUAN
messages regardless of the urbb_len.

Related: OS#1793

Change-Id: I00662a564f64c0c83627401ae8f7bfef0f0a5de8
3 files changed