V2 topBarTransparent (#2252)

lib/ios/RNNNavigationOptions.m

 			viewController.navigationController.navigationBar.translucent = [self.topBar.translucent boolValue];
 		}
 		
+		if (self.topBar.transparent) {
+			[viewController.navigationController.navigationBar setBackgroundImage:[UIImage new] forBarMetrics:UIBarMetricsDefault];
+			viewController.navigationController.navigationBar.shadowImage = [UIImage new];
+			UIView *transparentView = [[UIView alloc] initWithFrame:CGRectZero];
+			[viewController.navigationController.navigationBar insertSubview:transparentView atIndex:0];
+		}
+		
 		if (self.topBar.noBorder) {
 			if ([self.topBar.noBorder boolValue]) {
 				viewController.navigationController.navigationBar

lib/ios/RNNTopBarOptions.h

 @property (nonatomic, strong) NSNumber* hideOnScroll;
 @property (nonatomic, strong) NSNumber* buttonColor;
 @property (nonatomic, strong) NSNumber* translucent;
+@property (nonatomic, strong) NSNumber* transparent;
 @property (nonatomic, strong) NSNumber* textFontSize;
 @property (nonatomic, strong) NSNumber* noBorder;
 @property (nonatomic, strong) NSNumber* blur;

lib/ios/RNNTopBarOptions.m

 	self.buttonColor = [topBarOptions valueForKey:@"buttonColor"];
 	self.blur = [topBarOptions valueForKey:@"blur"];
 	self.translucent = [topBarOptions valueForKey:@"translucent"];
+	self.transparent = [topBarOptions valueForKey:@"transparent"];
 	self.noBorder = [topBarOptions valueForKey:@"noBorder"];
 	self.animateHide =[topBarOptions valueForKey:@"animateHide"];
 	

lib/ios/ReactNativeNavigationTests/RNNRootViewControllerTest.m

 	XCTAssertFalse(self.uut.navigationController.navigationBar.translucent);
 }
 
+-(void)testTopBarTransparent {
+	NSNumber* topBarTransparentInput = @(0);
+	self.options.topBar.transparent = topBarTransparentInput;
+	__unused RNNNavigationController* nav = [[RNNNavigationController alloc] initWithRootViewController:self.uut];
+	[self.uut viewWillAppear:false];
+	XCTAssertNotNil(self.uut.navigationController.navigationBar.shadowImage);
+	XCTAssertNotNil([self.uut.navigationController.navigationBar backgroundImageForBarMetrics:UIBarMetricsDefault]);
+	XCTAssertTrue(CGRectEqualToRect(self.uut.navigationController.navigationBar.subviews.firstObject.frame, CGRectZero));
+}
+
 -(void)testTabBadge {
 	NSString* tabBadgeInput = @"5";
 	self.options.tabBar.tabBadge = tabBadgeInput;