fix(ios): ios 13 change selection bug

Author: georgelima

ios/RNSelectableTextView.m

@@ -247,7 +247,28 @@ - (BOOL)canPerformAction:(SEL)action withSender:(id)sender
 
 - (UIView *)hitTest:(CGPoint)point withEvent:(UIEvent *)event
 {
-    [_backedTextInputView setSelectedTextRange:nil notifyDelegate:true];
+    if (!_backedTextInputView.isFirstResponder) {
+        [_backedTextInputView setSelectedTextRange:nil notifyDelegate:true];
+    } else {
+        UIView *sub = nil;
+        for (UIView *subview in self.subviews.reverseObjectEnumerator) {
+            CGPoint subPoint = [subview convertPoint:point toView:self];
+            UIView *result = [subview hitTest:subPoint withEvent:event];
+
+            if (!result.isFirstResponder) {
+                NSString *name = NSStringFromClass([result class]);
+
+                if ([name isEqual:@"UITextRangeView"]) {
+                    sub = result;
+                }
+            }
+        }
+        
+        if (sub == nil) {
+            [_backedTextInputView setSelectedTextRange:nil notifyDelegate:true];
+        }
+    }
+
     return [super hitTest:point withEvent:event];
 }