Controls UI - Direct 'add controls' to the proper activity

If there's more than one structure, set to the proper page in the
ViewPager. Fix the backstack so 'see other apps' works properly.

Bug: 153017283
Test: manual, use 'add controls' menu

Change-Id: Ie99537dee841817c8d790e00fe50c800a90c6158
2 files changed