[Release 1.25] Update Kube-router ACCEPT rule insertion and install script to clean rules before start

[rbrtbnfgl]

Proposed Changes

Backport for #7274

Types of Changes

Verification

Testing

Linked Issues

#7219

User-Facing Change

The embedded kube-router controller has been updated to fix a regression that caused traffic from pods to be blocked by any default drop/deny rules present on the host. Users should still confirm that any externally-managed firewall rules explicitly allow traffic to/from pod and service networks, but this returns the old behavior that was relied upon by some users.

Further Comments