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/rust.go b/rust/rust.go
index d8a0444..2e3d846 100644
--- a/rust/rust.go
+++ b/rust/rust.go
@@ -61,6 +61,7 @@
 	SnapshotInfo                  *cc.SnapshotInfo
 	SourceProviderInfo            *SourceProviderInfo
 	XrefRustFiles                 android.Paths
+	DocTimestampFile              android.OptionalPath
 }
 
 var RustInfoProvider = blueprint.NewProvider[*RustInfo]()
@@ -1173,6 +1174,7 @@
 		RustSubName:                   mod.Properties.RustSubName,
 		TransitiveAndroidMkSharedLibs: mod.transitiveAndroidMkSharedLibs,
 		XrefRustFiles:                 mod.XrefRustFiles(),
+		DocTimestampFile:              mod.docTimestampFile,
 	}
 	if mod.compiler != nil {
 		rustInfo.CompilerInfo = &CompilerInfo{