Use env varialbes to replace image urls & tags

Change-Id: I52421a03ddfb88fbad95eef8755c4d8e9c376705
Signed-off-by: ecaiyanlinux <martin.c.yan@est.tech>
Issue-ID: NONRTRIC-560
diff --git a/docker-compose/policy-service/docker-compose.yaml b/docker-compose/policy-service/docker-compose.yaml
index a593e2e..2dfc38c 100644
--- a/docker-compose/policy-service/docker-compose.yaml
+++ b/docker-compose/policy-service/docker-compose.yaml
@@ -22,7 +22,7 @@
 
 services:
   policy-agent:
-    image: nexus3.o-ran-sc.org:10004/o-ran-sc/nonrtric-policy-agent:2.3.0
+    image: "${PMS_IMAGE_BASE}:${PMS_IMAGE_TAG}"
     container_name: policy-agent
     networks:
       default: