fix iOS11 safeArea - #1858

ios/RCCViewController.m

@@ -288,10 +288,24 @@ - (void)_traverseAndCall:(UIView*)view
   }];
 }
 
+// fix iOS11 safeArea - https://github.com/facebook/react-native/issues/15681
+// rnn issue - https://github.com/wix/react-native-navigation/issues/1858
+- (void)_traverseAndFixScrollViewSafeArea:(UIView *)view {
+#ifdef __IPHONE_11_0
+  if ([view isKindOfClass:UIScrollView.class]) {
+    [((UIScrollView*)view) setContentInsetAdjustmentBehavior:UIScrollViewContentInsetAdjustmentNever];
+  }
+
+  [view.subviews enumerateObjectsUsingBlock:^(__kindof UIView * _Nonnull obj, NSUInteger idx, BOOL * _Nonnull stop) {
+    [self _traverseAndFixScrollViewSafeArea:obj];
+  }];
+#endif
+
+}
+
 - (void)viewDidAppear:(BOOL)animated
 {
   [super viewDidAppear:animated];
-
   [self sendGlobalScreenEvent:@"didAppear" endTimestampString:[self getTimestampString] shouldReset:YES];
   [self sendScreenChangedEvent:@"didAppear"];
 
@@ -300,6 +314,7 @@ - (void)viewDidAppear:(BOOL)animated
 - (void)viewWillAppear:(BOOL)animated
 {
   [super viewWillAppear:animated];
+  [self _traverseAndFixScrollViewSafeArea:self.view];
   [self sendGlobalScreenEvent:@"willAppear" endTimestampString:[self getTimestampString] shouldReset:NO];
   [self sendScreenChangedEvent:@"willAppear"];
   [self setStyleOnAppear];