Update memory limits and heapOpts for kafka

Change-Id: I0212d1b2c6b7dab3e7ce30227cba50361d1bb346
Signed-off-by: garciadeblas <gerardo.garciadeblas@telefonica.com>

installers/helm/osm/values.yaml

@@ -208,6 +208,10 @@ kafka:
   replicaCount: 1
   controller:
     replicaCount: 1
+    resources:
+      limits:
+        memory: 1024Mi
+    heapOpts: -Xmx768m -Xms768m
   extraConfigYaml:
     default.replication.factor: 1
     offsets.topic.replication.factor: 1