TUN-8427: Fix BackoffHandler's internally shared clock structure

A clock structure was used to help support unit testing timetravel
but it is a globally shared object and is likely unsafe to share
across tests. Reordering of the tests seemed to have intermittent
failures for the TestWaitForBackoffFallback specifically on windows
builds.

Adjusting this to be a shim inside the BackoffHandler struct should
resolve shared object overrides in unit testing.

Additionally, added the reset retries functionality to be inline with
the ResetNow function of the BackoffHandler to align better with
expected functionality of the method.

Removes unused reconnectCredentialManager.

supervisor/supervisor.go

@@ -49,8 +49,6 @@ type Supervisor struct {
 	log          *ConnAwareLogger
 	logTransport *zerolog.Logger
 
-	reconnectCredentialManager *reconnectCredentialManager
-
 	reconnectCh       chan ReconnectSignal
 	gracefulShutdownC <-chan struct{}
 }
@@ -76,8 +74,6 @@ func NewSupervisor(config *TunnelConfig, orchestrator *orchestration.Orchestrato
 		return nil, err
 	}
 
-	reconnectCredentialManager := newReconnectCredentialManager(connection.MetricsNamespace, connection.TunnelSubsystem, config.HAConnections)
-
 	tracker := tunnelstate.NewConnTracker(config.Log)
 	log := NewConnAwareLogger(config.Log, tracker, config.Observer)
 
@@ -87,7 +83,6 @@ func NewSupervisor(config *TunnelConfig, orchestrator *orchestration.Orchestrato
 	edgeTunnelServer := EdgeTunnelServer{
 		config:            config,
 		orchestrator:      orchestrator,
-		credentialManager: reconnectCredentialManager,
 		edgeAddrs:         edgeIPs,
 		edgeAddrHandler:   edgeAddrHandler,
 		edgeBindAddr:      edgeBindAddr,
@@ -98,18 +93,17 @@ func NewSupervisor(config *TunnelConfig, orchestrator *orchestration.Orchestrato
 	}
 
 	return &Supervisor{
-		config:                     config,
-		orchestrator:               orchestrator,
-		edgeIPs:                    edgeIPs,
-		edgeTunnelServer:           &edgeTunnelServer,
-		tunnelErrors:               make(chan tunnelError),
-		tunnelsConnecting:          map[int]chan struct{}{},
-		tunnelsProtocolFallback:    map[int]*protocolFallback{},
-		log:                        log,
-		logTransport:               config.LogTransport,
-		reconnectCredentialManager: reconnectCredentialManager,
-		reconnectCh:                reconnectCh,
-		gracefulShutdownC:          gracefulShutdownC,
+		config:                  config,
+		orchestrator:            orchestrator,
+		edgeIPs:                 edgeIPs,
+		edgeTunnelServer:        &edgeTunnelServer,
+		tunnelErrors:            make(chan tunnelError),
+		tunnelsConnecting:       map[int]chan struct{}{},
+		tunnelsProtocolFallback: map[int]*protocolFallback{},
+		log:                     log,
+		logTransport:            config.LogTransport,
+		reconnectCh:             reconnectCh,
+		gracefulShutdownC:       gracefulShutdownC,
 	}, nil
 }
 
@@ -138,7 +132,7 @@ func (s *Supervisor) Run(
 	var tunnelsWaiting []int
 	tunnelsActive := s.config.HAConnections
 
-	backoff := retry.BackoffHandler{MaxRetries: s.config.Retries, BaseTime: tunnelRetryDuration, RetryForever: true}
+	backoff := retry.NewBackoff(s.config.Retries, tunnelRetryDuration, true)
 	var backoffTimer <-chan time.Time
 
 	shuttingDown := false
@@ -212,7 +206,7 @@ func (s *Supervisor) initialize(
 		s.config.HAConnections = availableAddrs
 	}
 	s.tunnelsProtocolFallback[0] = &protocolFallback{
-		retry.BackoffHandler{MaxRetries: s.config.Retries, RetryForever: true},
+		retry.NewBackoff(s.config.Retries, retry.DefaultBaseTime, true),
 		s.config.ProtocolSelector.Current(),
 		false,
 	}
@@ -234,7 +228,7 @@ func (s *Supervisor) initialize(
 	// At least one successful connection, so start the rest
 	for i := 1; i < s.config.HAConnections; i++ {
 		s.tunnelsProtocolFallback[i] = &protocolFallback{
-			retry.BackoffHandler{MaxRetries: s.config.Retries, RetryForever: true},
+			retry.NewBackoff(s.config.Retries, retry.DefaultBaseTime, true),
 			// Set the protocol we know the first tunnel connected with.
 			s.tunnelsProtocolFallback[0].protocol,
 			false,