[DNM] Apply tagged cockroachdb image

This patch applies a tagged cockroachdb image for the interop demo. It's
a temporary patch only for the demo day.

Change-Id: I5cd02103cecc4cfad43f3f75823ba5ada927cb65

workloads/ansible/shade/k8s/roles/apps/templates/cockroachdb-pod.j2

@@ -2,7 +2,7 @@
 apiVersion: v1
 kind: Pod
 metadata:
-  name: cockroachdb-{{ inter_name }}
+  name: cockroachdb-{{ env.lower() }}-{{ inter_name }}
   labels:
     app: cockroachdb
 spec:
@@ -10,7 +10,7 @@ spec:
   restartPolicy: Always
   containers:
   - name: cockroachdb
-    image: cockroachdb/cockroach
+    image: cockroachdb/cockroach:interop-demo
     imagePullPolicy: IfNotPresent
     ports:
     - containerPort: 26257

workloads/ansible/shade/k8s/roles/post/templates/cockroachdb-init-pod.j2

@@ -1,7 +1,7 @@
 apiVersion: v1
 kind: Pod
 metadata:
-  name: cockroachdb-{{ inter_name }}
+  name: cockroachdb-{{ env.lower() }}-{{ inter_name }}
   labels:
     app: cockroachdb
 spec:
@@ -9,7 +9,7 @@ spec:
   restartPolicy: Always
   containers:
   - name: cockroachdb
-    image: cockroachdb/cockroach
+    image: cockroachdb/cockroach:interop-demo
     imagePullPolicy: IfNotPresent
     ports:
     - containerPort: 26257

workloads/ansible/shade/k8s/roles/post/templates/dashboard.j2

@@ -49,7 +49,7 @@ spec:
       containers:
       - name: kubernetes-dashboard
         image: gcr.io/google_containers/kubernetes-dashboard-amd64:v1.5.0
-        imagePullPolicy: Always
+        imagePullPolicy: IfNotPresent
         ports:
         - containerPort: 9090
           protocol: TCP