disabled back gesture support (#2273)

* disabled back gesture support

* changed disabledBackGesture prop name to popGesture

README.md

 |--------------------|-----|----|-----|
 | screenBackgroundColor        |   ✅     |     [Contribute](/docs/docs/CONTRIBUTING.md)       |  Wix|
 | orientation       |    ✅     |   [Contribute](/docs/docs/CONTRIBUTING.md)          | Wix|
-| disabledBackGesture        |  WIP @gran33     |    / iOS specific     |
+| disabledBackGesture        |    ✅     |    / iOS specific     |
 | screenBackgroundImageName        |   [Contribute](/docs/docs/CONTRIBUTING.md)      |    [Contribute](/docs/docs/CONTRIBUTING.md)        |
 | rootBackgroundImageName              |    [Contribute](/docs/docs/CONTRIBUTING.md)     |    [Contribute](/docs/docs/CONTRIBUTING.md)       |
 | sideMenuVisible          |        [Contribute](/docs/docs/CONTRIBUTING.md)   | [Contribute](/docs/docs/CONTRIBUTING.md) |
 | orientation     |  ✅   |    ✅     |   [Contribute](/docs/docs/CONTRIBUTING.md)          | Wix|
 | statusBarHideWithTopBar        |  ✅   |   ✅     |     [Contribute](/docs/docs/CONTRIBUTING.md)       | @gtchance|
 | statusBarHidden       |  ✅   |    ✅       |     [Contribute](/docs/docs/CONTRIBUTING.md)      | WIX |
-| disabledBackGesture       |   ✅  |  WIP @gran33     |    / iOS specific     |
+| disabledBackGesture       |   ✅  |   ✅  |    / iOS specific     |
 | screenBackgroundImageName         |   ✅  |   [Contribute](/docs/docs/CONTRIBUTING.md)      |    [Contribute](/docs/docs/CONTRIBUTING.md)        |
 | rootBackgroundImageName            |  ✅   |    [Contribute](/docs/docs/CONTRIBUTING.md)     |    [Contribute](/docs/docs/CONTRIBUTING.md)       |
 | setButtons          |   ✅     |    ✅    | [Contribute](/docs/docs/CONTRIBUTING.md) | @Johan-dutoit|

lib/ios/RNNNavigationOptions.h

 @property (nonatomic, strong) NSArray* rightButtons;
 @property (nonatomic, strong) NSNumber* statusBarBlur;
 @property (nonatomic, strong) NSNumber* statusBarHideWithTopBar;
+@property (nonatomic, strong) NSNumber* popGesture;
 @property (nonatomic, strong) RNNTopBarOptions* topBar;
 @property (nonatomic, strong) RNNTabBarOptions* tabBar;
 

lib/ios/RNNNavigationOptions.m

 		}
 	}
 	
+	if (self.popGesture) {
+		viewController.navigationController.interactivePopGestureRecognizer.enabled = [self.popGesture boolValue];
+	}
+	
 	if (self.screenBackgroundColor) {
 		UIColor* screenColor = [RCTConvert UIColor:self.screenBackgroundColor];
 		viewController.view.backgroundColor = screenColor;

lib/ios/ReactNativeNavigationTests/RNNRootViewControllerTest.m

 	XCTAssertTrue([self.uut.view.backgroundColor isEqual:expectedColor]);
 }
 
+-(void)testPopGestureEnabled_true{
+	NSNumber* popGestureEnabled = @(1);
+	self.options.popGesture = popGestureEnabled;
+	__unused UINavigationController* nav = [[RNNNavigationController alloc] initWithRootViewController:self.uut];
+	[self.uut viewWillAppear:false];
+	XCTAssertTrue(self.uut.navigationController.interactivePopGestureRecognizer.enabled);
+}
+
+-(void)testPopGestureEnabled_false{
+	NSNumber* popGestureEnabled = @(0);
+	self.options.popGesture = popGestureEnabled;
+	__unused UINavigationController* nav = [[RNNNavigationController alloc] initWithRootViewController:self.uut];
+	[self.uut viewWillAppear:false];
+	XCTAssertFalse(self.uut.navigationController.interactivePopGestureRecognizer.enabled);
+}
+
 -(void)testTopBarTextFontFamily_validFont{
 	NSString* inputFont = @"HelveticaNeue";
 	__unused RNNNavigationController* nav = [[RNNNavigationController alloc] initWithRootViewController:self.uut];