use same persistent volume as mediaserver

k8s-manifests/imageserver-deployment.yml

@@ -25,7 +25,7 @@ spec:
                 protocol: TCP
             imagePullPolicy: Always
             volumeMounts:
-              - name: image-volume
+              - name: av-volume
                 mountPath: /home/cantaloupe/images
             env:
               - name: CACHE_SERVER_DERIVATIVE_ENABLED
@@ -36,6 +36,6 @@ spec:
                 value: 'redis-service'
       restartPolicy: Always
       volumes:
-          - name: image-volume
+          - name: av-volume
             persistentVolumeClaim:
-                claimName: imageserver-volume-claim
+                claimName: av-volume-claim