fix missing selection indicator lines in PickerIOS

React/Views/RCTPicker.m

@@ -23,6 +23,7 @@ - (instancetype)initWithFrame:(CGRect)frame
     _selectedIndex = NSNotFound;
     _textAlign = NSTextAlignmentCenter;
     self.delegate = self;
+    [self selectRow:0 inComponent:0 animated:YES]; // Workaround for missing selection indicator lines (see https://stackoverflow.com/questions/39564660/uipickerview-selection-indicator-not-visible-in-ios10)
   }
   return self;
 }