Changed default modalPresentationStyle to system default - fullScreen

lib/ios/RNNViewControllerPresenter.m

 	
 	UIViewController* viewController = self.bindedViewController;
 	[viewController rnn_setBackgroundImage:[options.backgroundImage getWithDefaultValue:nil]];
-	[viewController rnn_setModalPresentationStyle:[RCTConvert UIModalPresentationStyle:[options.modalPresentationStyle getWithDefaultValue:@"formSheet"]]];
+	[viewController rnn_setModalPresentationStyle:[RCTConvert UIModalPresentationStyle:[options.modalPresentationStyle getWithDefaultValue:@"fullScreen"]]];
 	[viewController rnn_setModalTransitionStyle:[RCTConvert UIModalTransitionStyle:[options.modalTransitionStyle getWithDefaultValue:@"coverVertical"]]];
 	[viewController rnn_setDrawBehindTopBar:[options.topBar.drawBehind getWithDefaultValue:NO]];
 	[viewController rnn_setNavigationItemTitle:[options.topBar.title.text getWithDefaultValue:nil]];