Fixes backButton doesn't update on childWillAppear

lib/ios/RNNNavigationControllerPresenter.m

 	[navigationController rnn_setNavigationBarLargeTitleFontFamily:[options.topBar.largeTitle.fontFamily getWithDefaultValue:nil] fontSize:[options.topBar.largeTitle.fontSize getWithDefaultValue:nil] color:[options.topBar.largeTitle.color getWithDefaultValue:nil]];
 	[navigationController rnn_setNavigationBarFontFamily:[options.topBar.title.fontFamily getWithDefaultValue:nil] fontSize:[options.topBar.title.fontSize getWithDefaultValue:nil] color:[options.topBar.title.color getWithDefaultValue:nil]];
 	[navigationController rnn_setBackButtonColor:[options.topBar.backButton.color getWithDefaultValue:nil]];
+	[navigationController rnn_setBackButtonIcon:[options.topBar.backButton.icon getWithDefaultValue:nil] withColor:[options.topBar.backButton.color getWithDefaultValue:nil] title:[options.topBar.backButton.showTitle getWithDefaultValue:YES] ? [options.topBar.backButton.title getWithDefaultValue:nil] : @""];
 }
 
 - (void)applyOptionsOnWillMoveToParentViewController:(RNNNavigationOptions *)options {

lib/ios/ReactNativeNavigationTests/RNNNavigationControllerPresenterTest.m

 @implementation RNNNavigationControllerPresenterTest
 
 - (void)setUp {
-    [super setUp];
+	[super setUp];
 	self.uut = [[RNNNavigationControllerPresenter alloc] init];
 	self.bindedViewController = [OCMockObject partialMockForObject:[RNNNavigationController new]];
 	[self.uut bindViewController:self.bindedViewController];
 	self.options = [[RNNNavigationOptions alloc] initEmptyOptions];
 }
 
-- (void)testApplyOptionsOnWillMoveToParent_shouldSetBackButtonOnBindedViewController_withDefaultValues {
-	[[_bindedViewController expect] rnn_setBackButtonIcon:nil withColor:nil title:nil];
-	[self.uut applyOptionsOnWillMoveToParentViewController:self.options];
-	[_bindedViewController verify];
-}
-
 - (void)testApplyOptions_shouldSetBackButtonColor_withDefaultValues {
 	[[_bindedViewController expect] rnn_setBackButtonColor:nil];
 	[self.uut applyOptions:self.options];
 	[_bindedViewController verify];
 }
 
-- (void)testApplyOptionsOnWillMoveToParent_shouldSetBackButtonOnBindedViewController_withIcon {
-    Image* image = [[Image alloc] initWithValue:[UIImage new]];
-    self.options.topBar.backButton.icon = image;
+
+- (void)testApplyOptions_shouldSetBackButtonOnBindedViewController_withTitle {
+	Text* title = [[Text alloc] initWithValue:@"Title"];
+	self.options.topBar.backButton.title = title;
+	[[_bindedViewController expect] rnn_setBackButtonIcon:nil withColor:nil title:title.get];
+	[self.uut applyOptions:self.options];
+	[_bindedViewController verify];
+}
+
+- (void)testApplyOptions_shouldSetBackButtonOnBindedViewController_withHideTitle {
+	Text* title = [[Text alloc] initWithValue:@"Title"];
+	self.options.topBar.backButton.title = title;
+	self.options.topBar.backButton.showTitle = [[Bool alloc] initWithValue:@(0)];
+	[[_bindedViewController expect] rnn_setBackButtonIcon:nil withColor:nil title:@""];
+	[self.uut applyOptions:self.options];
+	[_bindedViewController verify];
+}
+
+- (void)testApplyOptions_shouldSetBackButtonOnBindedViewController_withIcon {
+	Image* image = [[Image alloc] initWithValue:[UIImage new]];
+	self.options.topBar.backButton.icon = image;
 	[[_bindedViewController expect] rnn_setBackButtonIcon:image.get withColor:nil title:nil];
-	[self.uut applyOptionsOnWillMoveToParentViewController:self.options];
+	[self.uut applyOptions:self.options];
 	[_bindedViewController verify];
 }
 
 - (void)testApplyOptionsOnWillMoveToParent_shouldSetBackButtonOnBindedViewController_withTitle {
-    Text* title = [[Text alloc] initWithValue:@"Title"];
-    self.options.topBar.backButton.title = title;
-    [[_bindedViewController expect] rnn_setBackButtonIcon:nil withColor:nil title:title.get];
-    [self.uut applyOptionsOnWillMoveToParentViewController:self.options];
-    [_bindedViewController verify];
+	Text* title = [[Text alloc] initWithValue:@"Title"];
+	self.options.topBar.backButton.title = title;
+	[[_bindedViewController expect] rnn_setBackButtonIcon:nil withColor:nil title:title.get];
+	[self.uut applyOptionsOnWillMoveToParentViewController:self.options];
+	[_bindedViewController verify];
 }
 
 - (void)testApplyOptionsOnWillMoveToParent_shouldSetBackButtonOnBindedViewController_withHideTitle {
-    Text* title = [[Text alloc] initWithValue:@"Title"];
-    self.options.topBar.backButton.title = title;
-    self.options.topBar.backButton.showTitle = [[Bool alloc] initWithValue:@(0)];
-    [[_bindedViewController expect] rnn_setBackButtonIcon:nil withColor:nil title:@""];
-    [self.uut applyOptionsOnWillMoveToParentViewController:self.options];
-    [_bindedViewController verify];
+	Text* title = [[Text alloc] initWithValue:@"Title"];
+	self.options.topBar.backButton.title = title;
+	self.options.topBar.backButton.showTitle = [[Bool alloc] initWithValue:@(0)];
+	[[_bindedViewController expect] rnn_setBackButtonIcon:nil withColor:nil title:@""];
+	[self.uut applyOptionsOnWillMoveToParentViewController:self.options];
+	[_bindedViewController verify];
+}
+
+- (void)testApplyOptionsOnWillMoveToParent_shouldSetBackButtonOnBindedViewController_withIcon {
+	Image* image = [[Image alloc] initWithValue:[UIImage new]];
+	self.options.topBar.backButton.icon = image;
+	[[_bindedViewController expect] rnn_setBackButtonIcon:image.get withColor:nil title:nil];
+	[self.uut applyOptionsOnWillMoveToParentViewController:self.options];
+	[_bindedViewController verify];
 }
 
+- (void)testApplyOptionsOnWillMoveToParent_shouldSetBackButtonOnBindedViewController_withDefaultValues {
+	[[_bindedViewController expect] rnn_setBackButtonIcon:nil withColor:nil title:nil];
+	[self.uut applyOptionsOnWillMoveToParentViewController:self.options];
+	[_bindedViewController verify];
+}
+
+
+
 @end