Launcher restore state fixes:

> Creating PendingRequestArgs to store generic request info across
activity instances
> Storing the CALL_PHONE request in PendingRequestArgs

> Handling onActivityResult only after the workspace has loaded.
onActivityResult sometimes modifies launcher db when removing empty
screens, and any add action is also deferred until bindComplete.
This simplifies this logic.

> Always binding the restored page irrespective of pending result.
Before starting a request activity (bind widget permission, or
widget config activity or shortcut picker), workspace commits the
pending screen id to the DB. Hence the restore page is valid when
restore is called (onResume loads with currentPage instead of
restored page)

Bug: 28573143
Change-Id: I34be603cbeb2145f5caf0d18e016f50029e07df8