Keep app when opening floating window from recents panel

Start activity asynchronously by appending it to system's
message queue to let RecentsPanelView cleanly execute
dismissAndGoBack before the floating window gets started.

Change-Id: Ie9c74b9f0b39f3aee81c62246cdcae15de83ee0d
Dismiss IME when floating window is dismissed

Previously the IME would be stuck on screen if the
floating window was dismissed while it was showing.

Change-Id: I8ca61b07ed89bae85eabd8db23f87b6f1f0b179f
Signed-off-by: Evan Anderson <evan@thelinuxman.us>
Slim Recents: Launch as Floating App

Change-Id: Ie4f04100c0decd0e987e25a5b3edbd385a62bcb3