on Activity Created
Called when the fragment's activity has been created and this fragment's view hierarchy instantiated. It can be used to do final initialization once these pieces are in place, such as retrieving views or restoring state. It is also useful for fragments that use setRetainInstance to retain their instance, as this callback tells the fragment when it is fully associated with the new activity instance. This is called after onCreateView and before onStart.
Parameters
saved Instance State
If the fragment is being re-created from a previous saved state, this is the state.