Split LauncherActivityControllerHelper for Go

As Go will likely have very different implementation since it will be
replacing the app => overview animation, we split
LauncherActivityControllerHelper so that Go can override the class
completely.

Bug: 114136250
Test: Manul test NexusLauncher, Launcher3QuickStepGo, Launcher3IconRecents
Change-Id: Ia5554593ddafffe0f729a4658d0a37aed16d236b