Hardcode (noS1) PDU session ID to 10

Defacto, the PDU session ID for noS1 modes is already hardcoded, as
starting the nr-softmodem with --noS1 --default-pdu-id 1 leads to

    Assertion (entity != ((void *)0)) failed!
    In start_sdap_tun_gnb_first_ue_default_pdu_session() openair2/SDAP/nr_sdap/nr_sdap.c:163

Further, the --default-pdu-id parameter will be deactivated in a later
commit, and we cannot rely on it. Therefore:

- hardcode noS1 PDU ID (also used in --do-ra/--phy-test modes) to 10 and
  use in gNB&UE
- pass the PDU session ID used in SDAP entity initialization down to
  start_sdap_tun_gnb_first_ue_default_pdu_session() to always use the
  correct one

openair3/NAS/NR_UE/nr_nas_msg.c

@@ -2160,7 +2160,7 @@ void *nas_nrue(void *args_p)
       } break;
 
       case NAS_INIT_NOS1_IF: {
-        const int pdu_session_id = get_softmodem_params()->default_pdu_session_id;
+        const int pdu_session_id = DEFAULT_NOS1_PDU_ID;
         const char *ip = "10.0.1.2";
         const int qfi = 7;
         create_ue_ip_if(ip, NULL, nas->UE_id, pdu_session_id);