Refactor factories

Change module factories from returning a blueprint.Module and a list
of property structs to returning an android.Module, which holds the
list of property structs.

Test: build.ninja identical except for Factory: comment lines
Change-Id: Ica1d823f009db812c518f271a386fbff39c9766f

cc/object.go

@@ -17,8 +17,6 @@ package cc
 import (
 	"fmt"
 
-	"github.com/google/blueprint"
-
 	"android/soong/android"
 )
 
@@ -35,7 +33,7 @@ type objectLinker struct {
 	Properties ObjectLinkerProperties
 }
 
-func objectFactory() (blueprint.Module, []interface{}) {
+func objectFactory() android.Module {
 	module := newBaseModule(android.HostAndDeviceSupported, android.MultilibBoth)
 	module.linker = &objectLinker{
 		baseLinker: NewBaseLinker(),