remove kube-rbac-proxy reference

[shivaprasadmb]

What this PR does / why we need it:
This PR is to remove kube-rbac-proxy sidecar container from ndb-operator and utilieze controller runtime native authorization to secure metrics server.

Kube-rbac-proxy mainly helps to secure http communications to access controller metrics using token. Since the newer versions of operator-sdk and kube-builder have native support for the same kuberbac-proxy can be removed.

Advantages:

• reduces one container from ndb-operator.
• helps in reducing dependency on 3rd party tools.
• simplifies vulnerability management.

How Has This Been Tested?:

The testing is done based on kube-rbac-proxy capabilities. Comparison is done to check functionalities before and after removing kube-rbac-proxy.

Before removing kube-rbac-proxy

After removing kube-rbac-proxy

Special notes for your reviewer:

• removing kube-rbac-proxy helps in reducing dependency and maintain CVEs easily.

Release note:

use latest operator sdk version.
remove kube-rbac-proxy support.

[sasikanthmasini]

LGTM