Override EarlyModuleContext.Namespace

Make android.EarlyModuleContext return a *Namespace.

Test: m checkbuild
Change-Id: I4c29d5e69e90eb9b7afbefc1355f63991a3e3331
diff --git a/android/module.go b/android/module.go
index 6956167..436bdd1 100644
--- a/android/module.go
+++ b/android/module.go
@@ -97,6 +97,8 @@
 	GlobFiles(globPattern string, excludes []string) Paths
 	IsSymlink(path Path) bool
 	Readlink(path Path) string
+
+	Namespace() *Namespace
 }
 
 // BaseModuleContext is the same as blueprint.BaseModuleContext except that Config() returns
@@ -219,7 +221,6 @@
 	VisitAllModuleVariants(visit func(Module))
 
 	GetMissingDependencies() []string
-	Namespace() blueprint.Namespace
 }
 
 type Module interface {
@@ -1187,7 +1188,7 @@
 
 	var deps Paths
 
-	namespacePrefix := ctx.Namespace().(*Namespace).id
+	namespacePrefix := ctx.Namespace().id
 	if namespacePrefix != "" {
 		namespacePrefix = namespacePrefix + "-"
 	}
@@ -1498,6 +1499,10 @@
 	return e.kind == systemExtSpecificModule
 }
 
+func (e *earlyModuleContext) Namespace() *Namespace {
+	return e.EarlyModuleContext.Namespace().(*Namespace)
+}
+
 type baseModuleContext struct {
 	bp blueprint.BaseModuleContext
 	earlyModuleContext