Use keepnetwork/keep-client:v2.0.0-m4 for keep-maintainer on production (#3692)

Here we point the production instance of `keep-maintainer` to the latest
public Docker image, i.e `keepnetwork/keep-client:v2.0.0-m4` which
enables support for redemptions.

Author: nkuba

infrastructure/kube/keep-prd/keep-maintainer/kustomization.yaml

@@ -10,8 +10,8 @@ commonLabels:
 
 images:
   - name: keep-maintainer
-    newName: gcr.io/keep-prd-210b/keep-client
-    newTag: v2.0.0-m4-rc
+    newName: keepnetwork/keep-client
+    newTag: v2.0.0-m4
 
 configMapGenerator:
   - name: keep-maintainer-config