Dismiss import dialog after it's clicked

- The workflow we want to fix is opening account dialog from import dialog.

- Previously, we keep import dialog around until account is chosen; this
  workflow never worked well on rotation since Lollipop.

- Now, we dismiss import dialog to simplify the workflow; and since we
  dismiss the import dialog, we use activity as a listener.

- SelectAccountDialogFragment is used in:
   - import contacts
   - create a new group

Bug: 32502787

Test: manual - verify importing contacts and creating new groups
               work well after rotation when there's 0, 1, and 2+ accounts.

Change-Id: Ic8b9c3f9987aeb3867ab2100097c235088507bdb
4 files changed