Fix topBar.background.color for older iOS versions (#5712)

lib/ios/RNNNavigationOptions.h

 #import "RNNModalOptions.h"
 
 extern const NSInteger BLUR_TOPBAR_TAG;
-extern const NSInteger TOP_BAR_TRANSPARENT_TAG;
 
 @interface RNNNavigationOptions : RNNOptions
 

lib/ios/UINavigationBar+utils.m

 #import "UINavigationBar+utils.h"
 
-const NSInteger TOP_BAR_TRANSPARENT_TAG = 78264803;
 
 @implementation UINavigationBar (utils)
 
         [self getNavigaitonBarScrollEdgeAppearance].backgroundColor = color;
     } else {
         [super setBackgroundColor:color];
-        [self removeTransparentView];
+        self.barTintColor = color;
     }
 }
 
         [self getNavigaitonBarScrollEdgeAppearance].backgroundEffect = nil;
         
     } else {
-        if (![self viewWithTag:TOP_BAR_TRANSPARENT_TAG]){
-            UIView *transparentView = [[UIView alloc] initWithFrame:CGRectZero];
-            transparentView.backgroundColor = [UIColor clearColor];
-            transparentView.tag = TOP_BAR_TRANSPARENT_TAG;
-            [self insertSubview:transparentView atIndex:0];
-        }
-        
         [self setBackgroundColor:[UIColor clearColor]];
         self.shadowImage = [UIImage new];
         [self setBackgroundImage:[UIImage new] forBarMetrics:UIBarMetricsDefault];
     }
 }
 
-- (void)removeTransparentView {
-    UIView *transparentView = [self viewWithTag:TOP_BAR_TRANSPARENT_TAG];
-    if (transparentView){
-        [transparentView removeFromSuperview];
-    }
-}
-
 - (void)configureWithTransparentBackground {
     if (@available(iOS 13.0, *)) {
         [[self getNavigaitonBarStandardAppearance] configureWithTransparentBackground];

playground/ios/NavigationTests/RNNNavigationControllerTest.m

 	[self.uut setTopBarBackgroundColor:redColor];
 	[self.uut setTopBarBackgroundColor:nil];
 	
-	XCTAssertNil([self.uut.navigationBar viewWithTag:TOP_BAR_TRANSPARENT_TAG]);
 	XCTAssertNil(self.uut.navigationBar.barTintColor);
 	XCTAssertNil(self.uut.navigationBar.standardAppearance.backgroundColor);
 	XCTAssertNil(self.uut.navigationBar.compactAppearance.backgroundColor);

playground/ios/NavigationTests/RNNRootViewControllerTest.m

 
 }
 
--(void)testTopBarTransparent_BOOL_false {
-	UIColor* inputColor = [RCTConvert UIColor:@(0xFFFF0000)];
-	__unused RNNStackController* nav = [self createNavigationController];
-	self.options.topBar.background.color = [[Color alloc] initWithValue:inputColor];
-	[self.uut viewWillAppear:false];
-	UIView* transparentView = [self.uut.navigationController.navigationBar viewWithTag:TOP_BAR_TRANSPARENT_TAG];
-	XCTAssertFalse(transparentView);
-}
-
 -(void)testTopBarLargeTitle_default {
 	[self.uut viewWillAppear:false];