Add preparers for sysprop

Bug: 181070625
Test: m nothing
Change-Id: I3c9c36e7270b68ff7d354acb239b47441335a931
diff --git a/sysprop/sysprop_library.go b/sysprop/sysprop_library.go
index 892a16c..f1c2d0d 100644
--- a/sysprop/sysprop_library.go
+++ b/sysprop/sysprop_library.go
@@ -193,7 +193,11 @@
 }
 
 func init() {
-	android.RegisterModuleType("sysprop_library", syspropLibraryFactory)
+	registerSyspropBuildComponents(android.InitRegistrationContext)
+}
+
+func registerSyspropBuildComponents(ctx android.RegistrationContext) {
+	ctx.RegisterModuleType("sysprop_library", syspropLibraryFactory)
 }
 
 func (m *syspropLibrary) Name() string {