Add image_username and image_password to charms

This commit will allow us to pull images for OSM components from a
private docker registry, protected with username and password

Change-Id: I854028d6abbb1cae07c61692ba73d08825763212
Signed-off-by: David Garcia <david.garcia@canonical.com>
diff --git a/installers/charm/ro-k8s/reactive/spec_template.yaml b/installers/charm/ro-k8s/reactive/spec_template.yaml
index f4f7c9c..f2b3535 100644
--- a/installers/charm/ro-k8s/reactive/spec_template.yaml
+++ b/installers/charm/ro-k8s/reactive/spec_template.yaml
@@ -16,7 +16,10 @@
   scalePolicy: serial
 containers:
   - name: %(name)s
-    image: %(docker_image)s
+    imageDetails:
+      imagePath: %(image)s
+      username: %(image_username)s
+      password: %(image_password)s
     kubernetes:
       readinessProbe:
         httpGet: