Remove lookup for kube-api cidr, instead use standard default

General MR

Summary

• Resolves issue where the lookup against the Kubernetes api endpoint potentially changes post-deployment, which invalidates the netpol
• Aligns this netpol with the more common BB standard

NOTE: This will be invalidated when bb-common is fully integrated with the BB charts.

Relevant logs/screenshots

Linked Issue

#109 (closed)

Upgrade Notices

N/A

Related to #109 (closed)