fix: remove unused kube-rbac-proxy, protect metrics-addr

Remove unused patch for `kube-rbac-proxy`, protect `metrics-addr` by
moving it to localhost by default.

Signed-off-by: Andrey Smirnov <[email protected]>

Author: smira

config/default/manager_auth_proxy_patch.yaml

@@ -19,6 +19,7 @@ spec:
         - command:
             - /manager
           args:
+            - --metrics-addr=127.0.0.1:8080
             - --enable-leader-election
             - "--feature-gates=MachinePool=${EXP_MACHINE_POOL:=false}"
           image: controller:latest