Revert "Revert "Revert "Floating Window: Welcome back"""

This reverts commit 629e117a7f0c8b9365d21cac7016cc5e15768335.
Revert "Revert "Base: Floating window with multitasking""

This reverts commit 6390f5be3292ee19e94a13022f8c7354841b7552.

Conflicts:
	core/res/res/values/ag_strings.xml
	core/res/res/values/ag_symbols.xml

Change-Id: Id933b0d0bcde0a66d59ffe34deb5ee6bf8833744