OpenShift Container Platform 4 - router is failing to start-up because of missing capabilities

Issue

• Default ingress router pods are failing to start with the following error on OCP 4.6

  I0421 15:12:56.874448       1 template.go:403] router "msg"="starting router"  "version"="majorFromGit: \nminorFromGit: \ncommitFromGit: 0ced824c9667a259b75e963a16f3dda4b5d781f6\nversionFromGit: 4.0.0-232-g0ced824\ngitTreeState: clean\nbuildDate: 2021-03-13T04:55:39Z\n"
  I0421 15:12:56.878886       1 metrics.go:154] metrics "msg"="router health and metrics port listening on HTTP and HTTPS"  "address"="0.0.0.0:1936"
  I0421 15:12:56.884689       1 router.go:185] template "msg"="creating a new template router"  "writeDir"="/var/lib/haproxy"
  I0421 15:12:56.884746       1 router.go:263] template "msg"="router will coalesce reloads within an interval of each other"  "interval"="5s"
  I0421 15:12:56.885195       1 router.go:325] template "msg"="watching for changes"  "path"="/etc/pki/tls/private"
  I0421 15:12:56.885278       1 router.go:254] router "msg"="router is only using routes in namespaces matching labels"  "labels"=[{}]
  E0421 15:12:57.006318       1 haproxy.go:418] can't scrape HAProxy: dial unix /var/lib/haproxy/run/haproxy.sock: connect: no such file or directory
  E0421 15:12:57.033007       1 limiter.go:165] error reloading router: exit status 1
  [ALERT] 110/151257 (18) : Starting frontend public: cannot bind socket [0.0.0.0:80]
  [ALERT] 110/151257 (18) : Starting frontend public_ssl: cannot bind socket [0.0.0.0:443]
  E0421 15:13:03.170630       1 haproxy.go:418] can't scrape HAProxy: dial unix /var/lib/haproxy/run/haproxy.sock: connect: connection refused
  E0421 15:13:06.982344       1 haproxy.go:418] can't scrape HAProxy: dial unix /var/lib/haproxy/run/haproxy.sock: connect: connection refused
  E0421 15:13:07.156251       1 haproxy.go:418] can't scrape HAProxy: dial unix /var/lib/haproxy/run/haproxy.sock: connect: connection refused
  E0421 15:13:12.938030       1 haproxy.go:418] can't scrape HAProxy: dial unix /var/lib/haproxy/run/haproxy.sock: connect: connection refused
  I0421 15:13:33.134704       1 template.go:657] router "msg"="Shutdown requested, waiting 45s for new connections to cease"  
  E0421 15:13:33.158806       1 haproxy.go:418] can't scrape HAProxy: dial unix /var/lib/haproxy/run/haproxy.sock: connect: connection refused
  E0421 15:13:36.975186       1 haproxy.go:418] can't scrape HAProxy: dial unix /var/lib/haproxy/run/haproxy.sock: connect: connection refused
  E0421 15:13:37.156312       1 haproxy.go:418] can't scrape HAProxy: dial unix /var/lib/haproxy/run/haproxy.sock: connect: connection refused
  E0421 15:13:42.937910       1 haproxy.go:418] can't scrape HAProxy: dial unix /var/lib/haproxy/run/haproxy.sock: connect: connection refused