Call onViewCreated in DashboardFragment

To let fragment's view lifecycle owner passed in to controllers.

For UI usage, view lifecycle owner is the best choice, controller could
use this lifecycle owner to observe events and do UI related works.

Usage DataSaverController as first example.

Bug: 287005021
Test: Manually for DataSaverController
Change-Id: Id965ea3a24d61f4d0ec6735632944f41f72ba06a