K8s manifest files updated to use docker tag 7 instead of latest

Change-Id: I5cbec8d6c4aed6612121391254f9f7e4d8fa0e6c
Signed-off-by: garciadeblas <gerardo.garciadeblas@telefonica.com>
diff --git a/installers/docker/osm_pods/pol.yaml b/installers/docker/osm_pods/pol.yaml
index d6ca7cd..f6ba437 100644
--- a/installers/docker/osm_pods/pol.yaml
+++ b/installers/docker/osm_pods/pol.yaml
@@ -36,7 +36,7 @@
         command: ["sh", "-c", "until (nc -zvw1 kafka 9092 && nc -zvw1 mongo 27017); do sleep 3; done; exit 0"]
       containers:
       - name: pol
-        image: opensourcemano/pol:latest
+        image: opensourcemano/pol:7
         env:
          - name: OSMPOL_MESSAGE_HOST
            value: kafka