Recents: Launch as Floating App
Thanks AOSPA

https://github.com/AOSPA/android_frameworks_base/commit/7df8e91196d228086f372b98cc5ff87e83e07ca4

https://github.com/AOSPA/android_frameworks_base/commit/733002295ca4a36f5a5acc2fb350062a25f0ed2a
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