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/dmaap-mediator-java/docker-compose.yaml b/docker-compose/dmaap-mediator-java/docker-compose.yaml
index 1d53de4..5cfe809 100644
--- a/docker-compose/dmaap-mediator-java/docker-compose.yaml
+++ b/docker-compose/dmaap-mediator-java/docker-compose.yaml
@@ -22,7 +22,7 @@
 
 services:
   dmaap-mediator-java:
-    image: nexus3.o-ran-sc.org:10003/o-ran-sc/nonrtric-dmaap-adaptor:1.0.0-SNAPSHOT
+    image: "${DMAAP_MEDIATOR_JAVA_BASE}:${DMAAP_MEDIATOR_JAVA_TAG}"
     container_name: dmaap-mediator-java
     networks:
       - default