Return android.Module from BottomUpMutatorContext methods

Soong will never see modules that implement blueprint.Module but
not android.Module any more, make all the BottomUpMutatorContext
methods return android.Module.

Test: builds
Change-Id: I39a75dab02fcd24763c7b6a6bb558a5e138c5ad5
diff --git a/android/hooks.go b/android/hooks.go
index f8022d0..5d509a4 100644
--- a/android/hooks.go
+++ b/android/hooks.go
@@ -100,12 +100,12 @@
 	l.appendPrependHelper(props, proptools.PrependMatchingProperties)
 }
 
-func (l *loadHookContext) createModule(factory blueprint.ModuleFactory, name string, props ...interface{}) blueprint.Module {
-	return l.bp.CreateModule(factory, name, props...)
+func (l *loadHookContext) createModule(factory blueprint.ModuleFactory, name string, props ...interface{}) Module {
+	return bpModuleToModule(l.bp.CreateModule(factory, name, props...))
 }
 
-func (l *loadHookContext) createModuleInDirectory(factory blueprint.ModuleFactory, name, moduleDir string, props ...interface{}) blueprint.Module {
-	return l.bp.CreateModuleInDirectory(factory, name, moduleDir, props...)
+func (l *loadHookContext) createModuleInDirectory(factory blueprint.ModuleFactory, name, moduleDir string, props ...interface{}) Module {
+	return bpModuleToModule(l.bp.CreateModuleInDirectory(factory, name, moduleDir, props...))
 }
 
 type specifyDirectory struct {
@@ -130,8 +130,8 @@
 type createModuleContext interface {
 	Module() Module
 	HasMutatorFinished(mutatorName string) bool
-	createModule(blueprint.ModuleFactory, string, ...interface{}) blueprint.Module
-	createModuleInDirectory(blueprint.ModuleFactory, string, string, ...interface{}) blueprint.Module
+	createModule(blueprint.ModuleFactory, string, ...interface{}) Module
+	createModuleInDirectory(blueprint.ModuleFactory, string, string, ...interface{}) Module
 }
 
 func createModule(ctx createModuleContext, factory ModuleFactory, ext string, specifyDirectory specifyDirectory, props ...interface{}) Module {