BTS_Tests: fix expectations in TC_speech_no_rtp_tch[fh]

This testcase is currently passing for both -master and -latest
versions of osmo-bts, despite their behavior is different:

* the -latest is sending FACCH frames with dummy LAPDm func=UI,
* the -master is sending invalid speech frames with inverted CRC3.

There is a bug in the 'tr_bad_frame' template definition: we expect
the payload to be present, while in real BFIs it's omitted.  So these
two testcases would always pass, even if the IUT would be sending dummy
bursts or sending nothing at all, because they were designed to fail on
receipt of a never-matching TRAFFIC.ind template.

Let's fix this and align our expectations with the current behavior
of the -master version of osmo-bts.  Note that sending invalid speech
frames with inverted CRC3 is not osmo-bts-trx specific behavior;
it's actually a replicated behavior of DSP based osmo-bts-sysmo.

Change-Id: Ic680002f60e598cfeeb448c517581b3506355e5b
Related: osmo-bts.git I78106802a0aa4af39859c75d29fe0e77037899fe
Related: SYS#5919, OS#4823
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M bts/BTS_Tests.ttcn
1 file changed, 48 insertions(+), 13 deletions(-)