Provide possibility to release DRBs in RRC

- Currently no fields to store DRB release: need persist in ASN
  structure
- This will be revisited once there is E1 bearer release release

openair2/RRC/NR/nr_rrc_defs.h

@@ -238,6 +238,7 @@ typedef enum {
 typedef struct gNB_RRC_UE_s {
   drb_t                              established_drbs[MAX_DRBS_PER_UE];
   uint8_t                            DRB_active[MAX_DRBS_PER_UE];
+  NR_DRB_ToReleaseList_t            *DRB_ReleaseList;
 
   NR_SRB_INFO_TABLE_ENTRY Srb[maxSRBs]; // 3gpp max is 3 SRBs, number 1..3, we waste the entry 0 for code simplicity
   NR_MeasConfig_t                   *measConfig;

openair2/RRC/NR/rrc_gNB.c

@@ -672,7 +672,7 @@ void rrc_gNB_generate_dedicatedRRCReconfiguration(const protocol_ctxt_t *const c
                                    xid,
                                    SRBs,
                                    DRBs,
-                                   NULL,
+                                   ue_p->DRB_ReleaseList,
                                    NULL,
                                    NULL,
                                    dedicatedNAS_MessageList,
@@ -680,6 +680,9 @@ void rrc_gNB_generate_dedicatedRRCReconfiguration(const protocol_ctxt_t *const c
   LOG_DUMPMSG(NR_RRC,DEBUG_RRC,(char *)buffer,size,"[MSG] RRC Reconfiguration\n");
   freeSRBlist(SRBs);
   freeDRBlist(DRBs);
+  ASN_STRUCT_FREE(asn_DEF_NR_DRB_ToReleaseList, ue_p->DRB_ReleaseList);
+  ue_p->DRB_ReleaseList = NULL;
+
   LOG_I(NR_RRC, "[gNB %d] Frame %d, Logical Channel DL-DCCH, Generate RRCReconfiguration (bytes %d, UE RNTI %x)\n", ctxt_pP->module_id, ctxt_pP->frame, size, ue_p->rnti);
   LOG_D(NR_RRC,
         "[FRAME %05d][RRC_gNB][MOD %u][][--- PDCP_DATA_REQ/%d Bytes (rrcReconfiguration to UE %x MUI %d) --->][PDCP][MOD %u][RB %u]\n",