CI: Change frequency used by AW2S pipeline

• change frequency used by AW2S pipeline to avoid interference with other deployments (new center frequency = 3469.440 MHz)
• add 1x1 test case with multiple UEs

ci-scripts/yaml_files/sa_aw2s_gnb/docker-compose.yml

 services:
     oai-gnb:
-        image: oaisoftwarealliance/oai-gnb-aw2s:develop
+        image: ${REGISTRY:-oaisoftwarealliance}/oai-gnb-aw2s:${TAG:-develop}
         network_mode: "host"
         container_name: oai-gnb-aw2s
         cap_drop: