Ensured back button press isn't frozen
Ensured back button press isn't frozen

Select Notifications tab in Twitter sample and then go back on Android. It wouldn't do anything because the back press on the Home tab thought it was selected - it had a stale closure. So moved the back press outside of the freeze so the onPress has the latest data

grahammendick/navigation,grahammendick/navigation,grahammendick/navigation,grahammendick/navigation,grahammendick/navigation,grahammendick/navigation,grahammendick/navigation