Fix tintColor in SegmentedControlIOS component

Summary:
iOS 13 introduced a new design for `UISegmentedControl` and new APIs to control this. `[UISegmentedControl tintColor]` is now ignored.

We try to maintain backwards compatibility so the appearance is as close as possible to iOS 12.

Changelog:
Fix `tintColor` on SegmentedControlIOS

Reviewed By: shergin

Differential Revision: D17905892

fbshipit-source-id: 964ac64c8543660929c43b427dce4f78094b1255

Author: sammy-SC

React/Views/RCTSegmentedControl.m

@@ -39,6 +39,21 @@ - (void)setSelectedIndex:(NSInteger)selectedIndex
   super.selectedSegmentIndex = selectedIndex;
 }
 
+- (void)setTintColor:(UIColor *)tintColor
+{
+  [super setTintColor:tintColor];
+#if defined(__IPHONE_OS_VERSION_MAX_ALLOWED) && defined(__IPHONE_13_0) && \
+    __IPHONE_OS_VERSION_MAX_ALLOWED >= __IPHONE_13_0
+  if (@available(iOS 13.0, *)) {
+    [self setSelectedSegmentTintColor:tintColor];
+    [self setTitleTextAttributes:@{NSForegroundColorAttributeName: [UIColor whiteColor]}
+                        forState:UIControlStateSelected];
+    [self setTitleTextAttributes:@{NSForegroundColorAttributeName: tintColor}
+                        forState:UIControlStateNormal];
+  }
+#endif
+}
+
 - (void)didChange
 {
   _selectedIndex = self.selectedSegmentIndex;