Support HA for the endpoints controller

- The controller manager allows for multiple instances of the controller
  to run using leader election. By configuring leader election, one of
the instances of the controller (the leader) will run the
reconciler. All instances can serve the webhook though, but only on of
the instances will inject the containers per request.

This requires additional priveleges from an RBAC perspective that will
be a part of a helm commit.

subcommand/inject-connect/command.go

@@ -362,7 +362,8 @@ func (c *Command) Run(args []string) int {
 
 	mgr, err := ctrl.NewManager(ctrl.GetConfigOrDie(), ctrl.Options{
 		Scheme:             scheme,
-		LeaderElection:     false,
+		LeaderElection:     true,
+		LeaderElectionID:   "consul-controller-lock",
 		Host:               listenSplits[0],
 		Port:               port,
 		Logger:             zapLogger,