maintner/maintnerd: increase RAM in k8s config

Change-Id: Iae6d90aa6692d4eaf247bde6834115d1b21ba514
Reviewed-on: https://go-review.googlesource.com/127677
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Author: andybons

maintner/maintnerd/deployment-prod.yaml

@@ -31,6 +31,6 @@ spec:
         resources:
           requests:
             cpu: "1"
-            memory: "2Gi"
+            memory: "4Gi"
           limits:
-            memory: "2Gi"
+            memory: "6Gi"