Firebase iOS Codelab Swift

When I follow https://codelabs.developers.google.com/codelabs/firebase-ios-swift there are few issues:

1) In step 4. Create Firebase console Project in section Connect your iOS app, you can't use Bundle id "com.google.firebase.codelab.FriendlyChatSwift", because Apple won't let you run app on your device. Apple insists on unique bundle id. Maybe every user might want to insert her/his modified bundle id.
2) In step 5. Identify Users, there is no tab RULES. Maybe it is caused that database isn't created right away when project is created. Either it is missing in codelab or it is issue with creating project.
3) When I created database manually and inserted the snippet from codelab into RULES it is not possible to make it public. It looks like there is deprecated snippet in codelab. I get error: "Error saving rules - Line 1: mismatched input '{' expecting {'function', 'service', 'syntax'}".