Hide QS whenever user switch occurs

Test: In QS, switch between users, ensure that QS closes after
      "Switching to user..." dialog goes away
Test: In Settings, switch between users, ensure everything works the
      same as previously
Bug: 192134653
Bug: 181266300
Change-Id: I7dee4874d6097e6a864ed3e766a4f25beeebd603
2 files changed