bump mgr to 3Gi to handle snapshots

argocd/rook/rook-ceph-cluster-values.yaml

@@ -61,7 +61,7 @@ cephClusterSpec:
     mgr:
       limits:
         cpu: 0
-        memory: "1.5Gi"
+        memory: "3Gi"
       requests:
         cpu: 0
         memory: "512Mi"