Remove undefined rootView (#3542)

ios/RCCViewController.m

 }
 
 - (void)sendScreenChangedEvent:(NSString *)eventName {
-    if (self.rootView != nil) {
-        RCTRootView *rootView = self.rootView;
+    if (self.view != nil) {
+        RCTRootView *rootView = self.view;
         
         if (rootView.appProperties && rootView.appProperties[@"navigatorEventID"]) {
             
 }
 
 - (void)sendGlobalScreenEvent:(NSString *)eventName endTimestampString:(NSString *)endTimestampStr shouldReset:(BOOL)shouldReset {
-    if (self.rootView != nil){
-        RCTRootView *rootView = self.rootView;
+    if (self.view != nil){
+        RCTRootView *rootView = self.view;
         NSString *screenName = [rootView moduleName];
         
         [[[RCCManager sharedInstance] getBridge].eventDispatcher sendAppEventWithName:eventName body:@