Convert singletonModuleSingletonAdaptor, rustdocSingleton,
sizesSingleton, movedToApexLlndkLibraries and
allBuildFlagDeclarationsSingleton to use ModuleProxy.

Bug: 377723687
Test: Unit tests and compare the ninja json and mk files generated.
Change-Id: I90ea5599a55975b27e9ce6e91b20104849f5887f
diff --git a/rust/doc.go b/rust/doc.go
index fe20523..2fb6ba9 100644
--- a/rust/doc.go
+++ b/rust/doc.go
@@ -37,14 +37,14 @@
 		FlagWithArg("-C ", docDir.String()).
 		FlagWithArg("-D ", docDir.String())
 
-	ctx.VisitAllModules(func(module android.Module) {
-		if !module.Enabled(ctx) {
+	ctx.VisitAllModuleProxies(func(module android.ModuleProxy) {
+		if !android.OtherModuleProviderOrDefault(ctx, module, android.CommonModuleInfoKey).Enabled {
 			return
 		}
 
-		if m, ok := module.(*Module); ok {
-			if m.docTimestampFile.Valid() {
-				zipCmd.Implicit(m.docTimestampFile.Path())
+		if m, ok := android.OtherModuleProvider(ctx, module, RustInfoProvider); ok {
+			if m.DocTimestampFile.Valid() {
+				zipCmd.Implicit(m.DocTimestampFile.Path())
 			}
 		}
 	})