bsc: test RR Channel Release EARFCNs

Add a DCHAN and release to recently added SI2quater tests (because these tests
already configure various amounts of EARFCNs in osmo-bsc).

Verify that the RR Channel Release for CSFB contains all configured EARFCNs.

In GSM_RR_Types.ttcn, add coding for "Cell selection indicator after release of
all TCH and SDCCH IE".

In f_expect_chan_rel(), add optional arg csfb_expect_cells, and, if present,
decode the RR Channel Release message's L3 part, and in turn the Cell Selection
Indicator Value contained. Match against csfb_expect_cells.

In f_tc_si2quater_n_earfcns(), also compose a list of EARFCNs as found in the
RR Channel Release, and pass to f_expect_chan_rel().

Depends: I59e427e4ebb1c6af99b27a15c40fed82457ac8ab (osmo-bsc)
Change-Id: I882c5e1f70bcc4833fc837a95c900ce291919cc5
2 files changed