Defragment AccountSetupBasics

* This was an early attempt at fragmentation
* But it turned out that no fragment was needed here - it is
  not shared or reused in any way.
* Precursor to doing final layouts for the activity.
* Tested working:
    Automatic provider lookup
    Manual
    POP/IMAP and EAS flow modes (from accounts & sync)
    Force account creation intent
    Provider note
    Duplicate account detection

Change-Id: I434edd4b152391d36e70440873932db3ec1a1c99
6 files changed