[iOS] Enable back swipe gesture when a navBar is hidden. Resolves this issue: https://github.com/wix/react-native-navigation/issues/930 (#1391)

added 03d380f8a9 back and also applied this fix https://github.com/wix/react-native-navigation/issues/428#issuecomment-278268928 on top of it

ios/RCCViewController.m

@@ -26,6 +26,7 @@ const NSInteger TRANSPARENT_NAVBAR_TAG = 78264803;
 @property (nonatomic) BOOL _statusBarTextColorSchemeLight;
 @property (nonatomic, strong) NSDictionary *originalNavBarImages;
 @property (nonatomic, strong) UIImageView *navBarHairlineImageView;
+@property (nonatomic, weak) id <UIGestureRecognizerDelegate> originalInteractivePopGestureDelegate;
 @end
 
 @implementation RCCViewController
@@ -484,6 +485,21 @@ const NSInteger TRANSPARENT_NAVBAR_TAG = 78264803;
     self.navBarHairlineImageView.hidden = NO;
   }
   
+ //Bug fix: in case there is a interactivePopGestureRecognizer, it prevents react-native from getting touch events on the left screen area that the gesture handles
+ //overriding the delegate of the gesture prevents this from happening while keeping the gesture intact (another option was to disable it completely by demand)
+ self.originalInteractivePopGestureDelegate = nil;
+ if(self.navigationController.viewControllers.count > 1){
+   if (self.navigationController != nil && self.navigationController.interactivePopGestureRecognizer != nil)
+   {
+     id <UIGestureRecognizerDelegate> interactivePopGestureRecognizer = self.navigationController.interactivePopGestureRecognizer.delegate;
+     if (interactivePopGestureRecognizer != nil)
+     {
+       self.originalInteractivePopGestureDelegate = interactivePopGestureRecognizer;
+       self.navigationController.interactivePopGestureRecognizer.delegate = self;
+     }
+   }
+ }
+  
   NSString *navBarCustomView = self.navigatorStyle[@"navBarCustomView"];
   if (navBarCustomView && ![self.navigationItem.titleView isKindOfClass:[RCCCustomTitleView class]]) {
     if ([self.view isKindOfClass:[RCTRootView class]]) {
@@ -524,6 +540,12 @@ const NSInteger TRANSPARENT_NAVBAR_TAG = 78264803;
 
 -(void)setStyleOnDisappear {
   self.navBarHairlineImageView.hidden = NO;
+  
+  if (self.navigationController != nil && self.navigationController.interactivePopGestureRecognizer != nil && self.originalInteractivePopGestureDelegate != nil)
+  {
+    self.navigationController.interactivePopGestureRecognizer.delegate = self.originalInteractivePopGestureDelegate;
+    self.originalInteractivePopGestureDelegate = nil;
+  }
 }
 
 // only styles that can't be set on willAppear should be set here