Make the enabled property configurable

This allows using select statements with it.

Ignore-AOSP-First: This needs to be in a topic with changes in interal-only repositories, I'll cherrypick to aosp after.
Bug: 323382414
Test: m nothing --no-skip-soong-tests
Change-Id: I6f3efaaa3d82505e38a91ee4ba0e18e404360191

rust/doc.go

@@ -38,7 +38,7 @@ func (n *rustdocSingleton) GenerateBuildActions(ctx android.SingletonContext) {
 		FlagWithArg("-D ", docDir.String())
 
 	ctx.VisitAllModules(func(module android.Module) {
-		if !module.Enabled() {
+		if !module.Enabled(ctx) {
 			return
 		}