fix: include image in rollout patches for proper pod creation

apps/myapp/overlays/production/rollout-patch.yaml

@@ -14,6 +14,7 @@ spec:
     spec:
       containers:
       - name: myapp
+        image: nginx:alpine
         resources:
           requests:
             memory: "256Mi"

apps/myapp/overlays/staging/rollout-patch.yaml

@@ -14,6 +14,7 @@ spec:
     spec:
       containers:
       - name: myapp
+        image: nginx:alpine
         resources:
           requests:
             memory: "128Mi"