add type to modules created by LoadHookContext

Modules created by a LoadHookContext do not currently set a module type
when creating new modules, but it would make analysis of the
module-graph.json much easier if this module type information was available.

Bug: 174879786
Test: m json-module-graph && check that module which previously had a
    blank module type now have the field populated
Change-Id: I3be5d259694a1540d21deb8a665ec7bea3464054

android/register.go

@@ -59,6 +59,7 @@ func (t moduleType) register(ctx *Context) {
 
 var moduleTypes []moduleType
 var moduleTypesForDocs = map[string]reflect.Value{}
+var moduleTypeByFactory = map[reflect.Value]string{}
 
 type singleton struct {
 	// True if this should be registered as a pre-singleton, false otherwise.
@@ -140,6 +141,7 @@ func RegisterModuleType(name string, factory ModuleFactory) {
 // RegisterModuleType was a lambda.
 func RegisterModuleTypeForDocs(name string, factory reflect.Value) {
 	moduleTypesForDocs[name] = factory
+	moduleTypeByFactory[factory] = name
 }
 
 func RegisterSingletonType(name string, factory SingletonFactory) {
@@ -228,6 +230,10 @@ func ModuleTypeFactoriesForDocs() map[string]reflect.Value {
 	return moduleTypesForDocs
 }
 
+func ModuleTypeByFactory() map[reflect.Value]string {
+	return moduleTypeByFactory
+}
+
 // Interface for registering build components.
 //
 // Provided to allow registration of build components to be shared between the runtime