CI: adjust YAML files to speedup deployment/undeployment in rfsim5g

- `init: true` initializes the docker container with tini or alternative - it is
  used to collect all the processes and correctly pass the termination signal to
  them, this allows the docker container to be stopped without waiting 10 seconds
  to kill the container
- speeding up the healthchecks by reducing the interval from 1-10s to 0.5s during
  start period

Co-authored-by: Bartosz Podrygajlo <bartosz.podrygajlo@openairinterface.org>

ci-scripts/yaml_files/5g_rfsimulator_sidelink/docker-compose.yaml

@@ -18,6 +18,8 @@ services:
             - ../../conf_files/nrue.uicc.conf:/opt/oai-nr-ue/etc/nr-ue.conf
         healthcheck:
             test: /bin/bash -c "pgrep nr-uesoftmodem"
+            start_period: 10s
+            start_interval: 500ms
             interval: 10s
             timeout: 5s
             retries: 5
@@ -43,6 +45,8 @@ services:
             - ../../conf_files/nrue.uicc.conf:/opt/oai-nr-ue/etc/nr-ue.conf
         healthcheck:
             test: /bin/bash -c "pgrep nr-uesoftmodem"
+            start_period: 10s
+            start_interval: 500ms
             interval: 10s
             timeout: 5s
             retries: 5