registerContainerFragment
abstract fun registerContainerFragment(fragment: Fragment, savedInstanceState: Bundle?, tagToContainerId: Map<ComponentTag, Int>): PanelToFragmentAdapter
Registers the given fragment as a container for the NavApp components, allowing NavApp to retrieve containers based on the tagToContainerId mapping.
Once all ComponentTags expected through configureGroup are made available, NavApp will be initialized.
This method must be called before fragment's super Fragment.onCreate is called. Calling it later will be too late when fragments are being restored because the fragment factory registered as a result of this call is needed within Fragment.onCreate.