Replace FinalModule with IsFinalModule.

Bug: 377723687
Test: Compare generated mk and ninja files.
Change-Id: I287b5a56aebf5fed0911bf8fbfc968d7aebc0dea
diff --git a/android/singleton.go b/android/singleton.go
index 6438182..0754b0c 100644
--- a/android/singleton.go
+++ b/android/singleton.go
@@ -81,7 +81,7 @@
 	VisitAllModuleVariantProxies(module Module, visit func(proxy ModuleProxy))
 
 	PrimaryModule(module Module) Module
-	FinalModule(module Module) Module
+	IsFinalModule(module Module) bool
 
 	AddNinjaFileDeps(deps ...string)
 
@@ -273,8 +273,8 @@
 	return s.SingletonContext.PrimaryModule(module).(Module)
 }
 
-func (s *singletonContextAdaptor) FinalModule(module Module) Module {
-	return s.SingletonContext.FinalModule(module).(Module)
+func (s *singletonContextAdaptor) IsFinalModule(module Module) bool {
+	return s.SingletonContext.IsFinalModule(module)
 }
 
 func (s *singletonContextAdaptor) ModuleVariantsFromName(referer Module, name string) []Module {