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
diff --git a/cc/coverage.go b/cc/coverage.go
index b1c8783..0b4188f 100644
--- a/cc/coverage.go
+++ b/cc/coverage.go
@@ -16,6 +16,7 @@
 
 import (
 	"android/soong/android"
+
 	"github.com/google/blueprint"
 )