Merge remote-tracking branch 'origin/fix_analog_das' into integration_2026_w13 (!3968)

Fix DAS via index based beamforming

DAS implementation via index based analog beamforming was broken after !3715.
This MR fixes it.

openair1/SCHED_NR/phy_procedures_nr_gNB.c

@@ -72,11 +72,12 @@ int beam_index_allocation(bool das,
 {
   if (!common_vars->beam_id)
     return 0;
-  if (das)
-    return fapi_beam_index;
 
   AssertFatal(IS_BIT_SET(fapi_beam_index, 15), "Can't handle preconfigured DBM yet\n");
   int ru_beam_idx = fapi_beam_index & 0x7fff;
+  if (das)
+    return ru_beam_idx;
+
   int idx = -1;
   for (int j = 0; j < common_vars->num_beams_period; j++) {
     // L2 analog beam implementation is slot based, so we need to verify occupancy for the whole slot