Correct READMEs of docker-compose files to reflect config mounting

ci-scripts/yaml_files/5g_rfsimulator/README.md

@@ -244,14 +244,11 @@ Create entry for Second UE in docker-compose.yaml file as follows:
         privileged: true
         container_name: rfsim5g-oai-nr-ue2
         environment:
-            FULL_IMSI: '208990100001101'
-            FULL_KEY: 'fec86ba6eb707ed08905757b1bb44b8f'
-            OPC: 'C42449363BBAD02B66D16BC975D77CC1'
-            DNN: oai
-            NSSAI_SST: 1
             USE_ADDITIONAL_OPTIONS: -E --sa --rfsim -r 106 --numerology 1 -C 3619200000 --rfsimulator.serveraddr 192.168.71.140 --log_config.global_log_options level,nocolor,time
         depends_on:
             - oai-gnb
+        volumes:
+            - ../../conf_files/nrue.uicc.conf:/opt/oai-nr-ue/etc/nr-ue.conf
         networks:
             public_net:
                 ipv4_address: 192.168.71.151
@@ -496,13 +493,25 @@ INSERT INTO `users` VALUES ('208990100001101','1','55000000000000',NULL,'PURGED'
 
 As you can see, 2 other values shall match in the NR-UE section of `docker-compose.yaml`:
 
-OAI UE - 1
-* `FULL_IMSI: '208990100001100'`
-* `FULL_KEY: 'fec86ba6eb707ed08905757b1bb44b8f'`
+All the values such as IMSI and KEY are taken from the configuration file mounted into the container.
 
-OAI UE - 2
-* `FULL_IMSI: '208990100001101'`
-* `FULL_KEY: 'fec86ba6eb707ed08905757b1bb44b8f'`
+```yaml
+ oai-nr-ue:
+        [...]
+        volumes:
+            - ../../conf_files/nrue.uicc.conf:/opt/oai-nr-ue/etc/nr-ue.conf
+```
+
+with the config having:
+```libconfig
+uicc0 = {
+  imsi = "208990100001100";
+  key = "fec86ba6eb707ed08905757b1bb44b8f";
+  opc= "C42449363BBAD02B66D16BC975D77CC1";
+  dnn= "oai";
+  nssai_sst=1;
+}
+```
 
 We are also using a dedicated `oai-smf.conf` for the `SMF` container: the `oai` DNN shall match the one in  the NR-UE section of `docker-compose.yaml` (`DNN: oai`).