BTS_Tests.ttcn: fix: expect RSL_MEAS_RES messages

Since both Calypso PHY and trxcon (since OS#2988 is fixed) are
always sending the Measurement Reports in dedicated mode, the
test cases should expect to 'see' the RSL_MEAS_RES messages,
and ignore them if they are out of the testing scope.

This change makes the following test cases pass:

  - TC_rll_est_ind,
  - TC_rll_rel_ind_DCCH_0,
  - TC_rll_rel_ind_DCCH_3,
  - TC_rll_rel_ind_ACCH_0,
  - TC_rll_rel_ind_ACCH_3,

by adding the 'lazy' version of as_meas_res() alt-step.

Change-Id: I34227b981f76377c338fad4ff9560ba2042abce4
1 file changed