Fix: Avoid contentInsets overwrites scrollIndicatorInsets on iOS face…

…book#13025

Fix to avoid contentInsets always overwrites scrollIndicatorInsets of ScrollView/ListView.
According to issue facebook#13025 https://github.com/facebook/react-native/blob/a8391bde7d757d01521a6d12170fb9090c17a6a0/React/Views/RCTView.m#L299
always overide `scrollIndicatorInsets` when called and only works when `contentInsets` is not set.
We only need to worry about when `contentInsets` is set, We only have to check and reset it after `autoAdjustInsetsForView` is called.

React/Views/ScrollView/RCTScrollView.m

@@ -394,6 +394,7 @@ - (instancetype)initWithEventDispatcher:(RCTEventDispatcher *)eventDispatcher
     _automaticallyAdjustContentInsets = YES;
     _DEPRECATED_sendUpdatedChildFrames = NO;
     _contentInset = UIEdgeInsetsZero;
+    _scrollIndicatorInsets = UIEdgeInsetsZero;
     _contentSize = CGSizeZero;
     _lastClippedToRect = CGRectNull;
 
@@ -552,6 +553,10 @@ - (void)setContentInset:(UIEdgeInsets)contentInset
                     withScrollView:_scrollView
                       updateOffset:NO];
 
+  if (!UIEdgeInsetsEqualToEdgeInsets(scrollIndicatorInsets, _scrollIndicatorInsets)) {
+     _scrollView.scrollIndicatorInsets = scrollIndicatorInsets;
+  }
+
   _scrollView.contentOffset = contentOffset;
 }