Bring primary storage migration back into the adoption flow, and
provide a path for long-lived notifications to re-launch into the
Settings app. Also provide option to initiate migration if skipped
during wizard. For now, estmiate migration size and time based on
a Class 10 card.
Follow other callback refactoring.
Bug: 19993667
Change-Id: Ia0c28eb114bc6c8066c17b3142ed74f962140c91