Adresses #3530

lib/ios/RNNNavigationButtons.m

 
 -(void)setButtons:(NSArray*)buttons side:(NSString*)side animated:(BOOL)animated {
 	NSMutableArray *barButtonItems = [NSMutableArray new];
-	for (NSDictionary *button in buttons) {
+	NSArray* resolvedButtons = [self resolveButtons:buttons];
+	for (NSDictionary *button in resolvedButtons) {
 		RNNUIBarButtonItem* barButtonItem = [self buildButton:button];
 		if(barButtonItem) {
 			[barButtonItems addObject:barButtonItem];
 	}
 }
 
+- (NSArray *)resolveButtons:(id)buttons {
+	if ([buttons isKindOfClass:[NSArray class]]) {
+		return buttons;
+	} else {
+		return @[buttons];
+	}
+}
+
 -(RNNUIBarButtonItem*)buildButton: (NSDictionary*)dictionary {
 	NSString* buttonId = dictionary[@"id"];
 	NSString* title = dictionary[@"title"];

playground/src/screens/OptionsScreen.js

             color: 'red'
           }
         ],
-        leftButtons: [{
+        leftButtons: {
           id: BUTTON_LEFT,
           testID: BUTTON_LEFT,
           icon: require('../../img/navicon_add.png'),
           title: 'Left',
           color: 'purple'
-        }]
+        }
       },
       fab: {
         id: FAB,