Set scrollsToTop = NO for UITextViews

Summary: Complete the work from 853d5b2221 by also fixing the placeholder view.
Closes https://github.com/facebook/react-native/pull/3129

Reviewed By: @​svcscm

Differential Revision: D2499753

Pulled By: @vjeux

Libraries/Text/RCTTextView.m

@@ -78,6 +78,7 @@ RCT_NOT_IMPLEMENTED(- (instancetype)initWithCoder:(NSCoder *)aDecoder)
     _placeholderView = [[UITextView alloc] initWithFrame:self.bounds];
     _placeholderView.backgroundColor = [UIColor clearColor];
     _placeholderView.scrollEnabled = false;
+    _placeholderView.scrollsToTop = NO;
     _placeholderView.attributedText =
     [[NSAttributedString alloc] initWithString:_placeholder attributes:@{
       NSFontAttributeName : (_textView.font ? _textView.font : [self defaultPlaceholderFont]),