[ios] Fix bug that reverts navbar title size to 17 (#5297)

lib/ios/RNNNavigationControllerPresenter.m

 - (void)applyOptionsBeforePopping:(RNNNavigationOptions *)options {
 	RNNNavigationController* navigationController = self.boundViewController;
 	[navigationController setTopBarBackgroundColor:[options.topBar.background.color getWithDefaultValue:nil]];
-	[navigationController rnn_setNavigationBarFontFamily:[options.topBar.title.fontFamily getWithDefaultValue:nil] fontSize:[options.topBar.title.fontSize getWithDefaultValue:@(17)] color:[options.topBar.title.color getWithDefaultValue:[UIColor blackColor]]];
+	[navigationController rnn_setNavigationBarFontFamily:[options.topBar.title.fontFamily getWithDefaultValue:nil] fontSize:[options.topBar.title.fontSize getWithDefaultValue:nil] color:[options.topBar.title.color getWithDefaultValue:[UIColor blackColor]]];
 	[navigationController rnn_setNavigationBarLargeTitleVisible:[options.topBar.largeTitle.visible getWithDefaultValue:NO]];
 }