Fix setting bottomTabs.currentTabIndex on bottomTabs init (#4457)

lib/ios/RNNTabBarController.m

 	self.presenter = presenter;
 	[self.presenter bindViewController:self];
 	[self setViewControllers:childViewControllers];
+	[self.presenter applyOptionsOnInit:self.options];
 	
 	return self;
 }

lib/ios/RNNTabBarPresenter.m

 
 @implementation RNNTabBarPresenter
 
+- (void)applyOptionsOnInit:(RNNNavigationOptions *)initialOptions {
+	UITabBarController* tabBarController = self.bindedViewController;
+	[tabBarController rnn_setCurrentTabIndex:[initialOptions.bottomTabs.currentTabIndex getWithDefaultValue:0]];
+}
+
 - (void)applyOptions:(RNNNavigationOptions *)options {
 	UITabBarController* tabBarController = self.bindedViewController;
 	

lib/ios/ReactNativeNavigationTests/RNNTabBarPresenterTest.m

 	[self.bindedViewController verify];
 }
 
-- (void)testApplyOptions_shouldSetInitialOptions {
+- (void)testApplyOptions_shouldApplyOptions {
 	RNNNavigationOptions* initialOptions = [[RNNNavigationOptions alloc] initEmptyOptions];
 	initialOptions.bottomTabs.testID = [[Text alloc] initWithValue:@"testID"];
 	initialOptions.bottomTabs.backgroundColor = [[Color alloc] initWithValue:[UIColor redColor]];
 	[self.bindedViewController verify];
 }
 
+- (void)testApplyOptions_shouldApplyOptionsOnInit {
+	RNNNavigationOptions* initialOptions = [[RNNNavigationOptions alloc] initEmptyOptions];
+	initialOptions.bottomTabs.currentTabIndex = [[IntNumber alloc] initWithValue:@(1)];
+	[[self.bindedViewController expect] rnn_setCurrentTabIndex:1];
+	
+	[self.uut applyOptionsOnInit:initialOptions];
+	[self.bindedViewController verify];
+}
+
 @end