Set kube-proxy memory request to 50Mi

With optional override using KUBE_PROXY_MEMORY_REQUEST following the
KUBE_PROXY_CPU_REQUEST pattern.

cluster/addons/kube-proxy/kube-proxy-ds.yaml

@@ -38,6 +38,7 @@ spec:
         resources:
           requests:
             cpu: {{ cpurequest }}
+            memory: {{ memoryrequest }}
         command:
         - /bin/sh
         - -c

cluster/gce/gci/configure-helper.sh

@@ -1783,6 +1783,7 @@ function prepare-kube-proxy-manifest-variables {
   sed -i -e "s@{{kube_cache_mutation_detector_env_name}}@${kube_cache_mutation_detector_env_name}@g" "${src_file}"
   sed -i -e "s@{{kube_cache_mutation_detector_env_value}}@${kube_cache_mutation_detector_env_value}@g" "${src_file}"
   sed -i -e "s@{{ cpurequest }}@${KUBE_PROXY_CPU_REQUEST:-100m}@g" "${src_file}"
+  sed -i -e "s@{{ memoryrequest }}@${KUBE_PROXY_MEMORY_REQUEST:-50Mi}@g" "${src_file}"
   sed -i -e "s@{{api_servers_with_port}}@${api_servers}@g" "${src_file}"
   sed -i -e "s@{{kubernetes_service_host_env_value}}@${KUBERNETES_MASTER_NAME}@g" "${src_file}"
   if [[ -n "${CLUSTER_IP_RANGE:-}" ]]; then

cluster/gce/manifests/kube-proxy.manifest

@@ -23,6 +23,7 @@ spec:
     resources:
       requests:
         cpu: {{ cpurequest }}
+        memory: {{ memoryrequest }}
     command:
     - /bin/sh
     - -c