Remove SetupActivity, perform setup in MainActivity

Squashed commit of the following:

commit ff6ece72a60917ceec3ea1485901e8929e65bb43
Author: Moez Bhatti <moez.bhatti@gmail.com>
Date:   Wed May 9 01:50:33 2018 -0400

    Remove default SMS UI from settings

commit 1ce79ea756259268c4d2fcd8acbee3101fdbe019
Author: Moez Bhatti <moez.bhatti@gmail.com>
Date:   Wed May 9 01:45:33 2018 -0400

    Remove SetupActivity, perform setup in MainActivity

commit ccad342d2ab8a5346d63dab273ba9cadb2fa62c0
Author: Moez Bhatti <moez.bhatti@gmail.com>
Date:   Mon May 7 18:02:26 2018 -0400

    Don't query ContentProvider without appropriate permission

commit 527be2e5331ba0cbfd6f3375c12378105d282b0c
Author: Moez Bhatti <moez.bhatti@gmail.com>
Date:   Mon May 7 17:12:00 2018 -0400

    Show non-blocking UI in MainActivity while syncing