Update Lifecycle direct extension's configuraiton keys to include the data type required

### Is there an existing issue for this?

- [x] I have searched the existing issues

### What's missing?

Current docs don't explain that the data type should be an int:
https://developer.adobe.com/client-sdks/home/base/mobile-core/lifecycle/configuration-keys/

and since a lot of config keys are strings, and the casting failure is silent, it's not obvious what value is being used:

```swift
private func getSessionTimeoutLength(configurationSharedState: [String: Any]?) -> TimeInterval {
guard let sessionTimeoutInt = configurationSharedState?[LifecycleConstants.EventDataKeys.CONFIG_SESSION_TIMEOUT] as? Int else {
return TimeInterval(LifecycleConstants.DEFAULT_LIFECYCLE_TIMEOUT)
}

return TimeInterval(sessionTimeoutInt)
}
```

Start with the Lifecycle configuration keys page linked in the issue and review how the session timeout key is documented. Update the documentation to state that its value must be an integer, and clarify the value expected by the Lifecycle extension. Done when users can identify the required data type from the page.

Written by the indexing model from the issue text.