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: Ie58ddc81b4ea897b4243404a58fae47583e49e1a

Conflicts:
	packages/SystemUI/src/com/android/systemui/recent/RecentsPanelView.java
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.

Original id from PA gerrit -> Change-Id: I8ca61b07ed89bae85eabd8db23f87b6f1f0b179f
Signed-off-by: Evan Anderson <evan@thelinuxman.us>

Change-Id: If38e65f61ba309d22306bf4b37c3c55630c006ed