Share CreateModule between hooks & mutators

These contained duplicate code, but evolved separately in the effort to
identify module type of those created with CreateModule. This refactors
to share a common implementation between the two.

Test: m json-module-graph and verify Type fields
Test: CI
Change-Id: Ifdb9a006d9b1bef7411f9ce3a4384797693b4bfc

android/mutator.go

@@ -15,12 +15,9 @@
 package android
 
 import (
-	"reflect"
-
 	"android/soong/bazel"
 
 	"github.com/google/blueprint"
-	"github.com/google/blueprint/proptools"
 )
 
 // Phases:
@@ -553,29 +550,16 @@ func (t *topDownMutatorContext) Rename(name string) {
 	t.Module().base().commonProperties.DebugName = name
 }
 
+func (t *topDownMutatorContext) createModule(factory blueprint.ModuleFactory, name string, props ...interface{}) blueprint.Module {
+	return t.bp.CreateModule(factory, name, props...)
+}
+
 func (t *topDownMutatorContext) CreateModule(factory ModuleFactory, props ...interface{}) Module {
-	inherited := []interface{}{&t.Module().base().commonProperties}
-	module := t.bp.CreateModule(ModuleFactoryAdaptor(factory), append(inherited, props...)...).(Module)
-
-	if t.Module().base().variableProperties != nil && module.base().variableProperties != nil {
-		src := t.Module().base().variableProperties
-		dst := []interface{}{
-			module.base().variableProperties,
-			// Put an empty copy of the src properties into dst so that properties in src that are not in dst
-			// don't cause a "failed to find property to extend" error.
-			proptools.CloneEmptyProperties(reflect.ValueOf(src)).Interface(),
-		}
-		err := proptools.AppendMatchingProperties(dst, src, nil)
-		if err != nil {
-			panic(err)
-		}
-	}
-
-	return module
+	return createModule(t, factory, "_topDownMutatorModule", props...)
 }
 
 func (t *topDownMutatorContext) createModuleWithoutInheritance(factory ModuleFactory, props ...interface{}) Module {
-	module := t.bp.CreateModule(ModuleFactoryAdaptor(factory), props...).(Module)
+	module := t.bp.CreateModule(ModuleFactoryAdaptor(factory), "", props...).(Module)
 	return module
 }