Fix race condition

Author: chizhavko

Diff for: Sources/MapboxNavigation/CPInterfaceController.swift

@@ -12,8 +12,8 @@ public extension CPInterfaceController {
      animated or not.
      */
     func safePopTemplate(animated: Bool) {
-        if templates.count >= 1 { return }
-        
+        guard templates.count > 1 else { return }
+
         popTemplate(animated: animated)
     }
 }

Diff for: Sources/MapboxNavigation/CarPlayManager.swift

@@ -102,7 +102,8 @@ public class CarPlayManager: NSObject {
     private weak var navigationService: NavigationService?
     private var idleTimerCancellable: IdleTimerManager.Cancellable?
     private var indexedRouteResponse: IndexedRouteResponse?
-    
+    private let semaphore = DispatchSemaphore(value: 1)
+
     /**
      Programatically begins a CarPlay turn-by-turn navigation session.
 
@@ -653,6 +654,9 @@ extension CarPlayManager {
     }
 
     func previewRoutes(for trip: CPTrip) {
+        semaphore.wait()
+        defer { semaphore.signal() }
+
         guard let traitCollection = (self.carWindow?.rootViewController as? CarPlayMapViewController)?.traitCollection,
               let interfaceController = interfaceController else {
                   return